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What bone protects the brain?
C3Skull
It's the bone at the very top of your body
What is the common name for the clavicle?
C3Collarbone
It connects your shoulder to your sternum
What is the common name for the scapula?
C3Shoulder blade
It's a flat triangular bone on your back
What is the large bone of the upper arm?
C3Humerus
Sounds like 'humorous' — and the funny bone area is actually near this bone!
Which forearm bone is on the thumb side?
C3Radius
It 'radiates' out to your thumb
Which forearm bone is on the pinky side?
C3Ulna
It forms the point of your elbow
What is the longest and strongest bone in the body?
C3Femur
It's in your upper leg
What is the common name for the tibia?
C3Shinbone
You can feel it on the front of your lower leg
What is the thin bone on the outer side of the lower leg?
C3Fibula
It runs parallel to the shinbone
What is the common name for the patella?
C3Kneecap
It protects the front of your knee joint
What large bone supports the weight of the upper body?
C3Pelvis
It's shaped like a basin and connects your legs to your spine
What is the common name for the sternum?
C3Breastbone
It's in the center of your chest
How many pairs of ribs does a human have?
C312 pairs (24 ribs total)
Same number as months in a year
What are the individual bones of the spine called?
C3Vertebrae
The spine is also called the vertebral column
How many bones are in the adult human body?
C3206
A baby has about 270, but they fuse together
What is the smallest bone in the human body?
C3Stapes
It's inside your ear
What are the three types of muscle tissue?
C3Skeletal, cardiac, and smooth
One is attached to bones, one is in the heart, one lines organs
Which type of muscle is voluntary and attached to bones?
C3Skeletal muscle
You control these muscles when you move
Which type of muscle is found only in the heart?
C3Cardiac muscle
Cardiac relates to the heart
Which type of muscle lines the walls of organs and blood vessels?
C3Smooth muscle
It's involuntary and looks smooth under a microscope
What muscle bends (flexes) your arm at the elbow?
C3Biceps
It's on the front of your upper arm
What muscle group on the front of the thigh straightens the knee?
C3Quadriceps
'Quad' means four — it's a group of four muscles
What muscle group on the back of the thigh bends the knee?
C3Hamstrings
They're behind your thigh, opposite the quads
List the main organs of the digestive system in order.
C3Mouth, esophagus, stomach, small intestine, large intestine, rectum
Food enters through your mouth and exits through the rectum
Where does digestion begin?
C3The mouth
Teeth and saliva start breaking down food
What tube carries food from the mouth to the stomach?
C3Esophagus
It uses muscle contractions called peristalsis
What organ uses acid to break down food into a soupy mixture?
C3Stomach
It contains hydrochloric acid
Where does most nutrient absorption take place?
C3Small intestine
It's about 20 feet long with tiny finger-like projections called villi
What organ absorbs water and forms solid waste?
C3Large intestine
It's wider but shorter than the small intestine
What organ produces bile to help digest fats?
C3Liver
It's the largest internal organ
What organ produces enzymes for digestion and insulin for blood sugar?
C3Pancreas
It has both digestive and hormonal functions
How many chambers does the human heart have?
C34
There are upper chambers (atria) and lower chambers (ventricles)
What blood vessels carry blood AWAY from the heart?
C3Arteries
Arteries = Away
What blood vessels carry blood TOWARD the heart?
C3Veins
They have valves to prevent blood from flowing backward
What are the smallest blood vessels where gas exchange occurs?
C3Capillaries
Their walls are only one cell thick
What blood cells carry oxygen throughout the body?
C3Red blood cells
They contain hemoglobin, which gives blood its red color
What blood cells fight infection and disease?
C3White blood cells
They are part of your immune system
What blood cells help stop bleeding by forming clots?
C3Platelets
When you get a cut, these rush to the wound
Name the main parts of the respiratory system.
C3Nose, trachea, bronchi, lungs (airway); diaphragm (breathing muscle)
Air enters through the nose and reaches the lungs; the diaphragm powers breathing
What is the common name for the trachea?
C3Windpipe
It carries air from your throat to your lungs
What are the two tubes that branch from the trachea into the lungs?
C3Bronchi
One goes to the left lung, one to the right
What dome-shaped muscle helps you breathe?
C3Diaphragm
It's located below the lungs and contracts when you inhale
What are the tiny air sacs in the lungs where gas exchange occurs?
C3Alveoli
They look like clusters of grapes
What gas do we breathe in that our cells need?
C3Oxygen
It makes up about 21% of the air
What gas do we breathe out as a waste product?
C3Carbon dioxide
Plants use this gas for photosynthesis
What is the largest part of the brain, responsible for thinking and memory?
C3Cerebrum
It has two hemispheres and a wrinkled surface
What part of the brain coordinates balance and movement?
C3Cerebellum
It's located at the back of the brain, below the cerebrum
What part of the brain controls involuntary actions like breathing and heartbeat?
C3Brain stem
It connects the brain to the spinal cord
What is a nerve cell called?
C3Neuron
It carries electrical signals throughout the body
What is the correct path of blood through the heart? (starting from the body)
C1Right atrium → right ventricle → lungs → left atrium → left ventricle → body
Remember: Right side pumps to Lungs, Left side pumps to Body (R-L, Lungs-Body)
What are the four main blood types?
C1A, B, AB, O
O negative is the universal red-cell donor
Which type of blood vessel has thick, muscular walls and carries oxygen-rich blood (usually)?
C1Arteries
They pulse with each heartbeat; 'A' for Away from heart, 'A' for Artery
What small organ stores bile produced by the liver?
C1Gallbladder
It releases bile into the small intestine when you eat fatty foods
What tiny finger-like projections in the small intestine absorb nutrients into the blood?
C1Villi
They increase the surface area for absorption — like a shag carpet
What long bundle of nerves runs through the vertebral column and relays messages between the brain and body?
C1Spinal cord
The backbone protects it; damage to it can cause paralysis
What are the two main divisions of the nervous system?
C1Central nervous system (CNS) and peripheral nervous system
Central = Center (brain & spine are in the center); Peripheral = edges (nerves reaching out to fingers, toes)
Where exactly does oxygen pass into the blood in the lungs?
C1In the alveoli, through the thin walls into surrounding capillaries
Both the air sac walls and blood vessel walls are only one cell thick
When you inhale, what happens to your diaphragm?
C1It contracts (flattens) and moves down, creating space for the lungs to expand
Contract = flatten = air rushes IN; relax = dome up = air goes OUT
What is the largest artery in the body?
C1Aorta
It carries oxygen-rich blood from the left ventricle to the rest of the body
When your elbow bends, which body systems work together most directly?
C3Skeletal and muscular systems
Bones give structure, muscles pull on bones
You touch a hot pan and pull back quickly before thinking carefully. Which system coordinates that fast response?
C3Nervous system
Nerves carry fast signals
List the four layers of the Earth from outside to inside.
C1Crust, mantle, outer core, inner core
The outermost is thin like an eggshell, the innermost is a solid ball
What is the thin, outermost layer of the Earth?
C1Crust
We live on this layer; it includes continents and ocean floor
What is the thickest layer of the Earth made of hot, dense rock?
C1Mantle
It slowly flows and causes tectonic plate movement
What layer of the Earth is liquid iron and nickel?
C1Outer core
It creates Earth's magnetic field
What layer of the Earth is solid iron and nickel at extreme pressure?
C1Inner core
It's the hottest part of the Earth but pressure keeps it solid
What type of rock forms from cooled magma or lava?
C1Igneous
'Ignis' is Latin for fire
What type of rock forms from layers of sediment compressed over time?
C1Sedimentary
It often contains fossils and forms in layers
What type of rock forms when existing rock is changed by heat and pressure?
C1Metamorphic
'Meta' means change — this rock has been transformed
What are the main steps of the water cycle?
C1Evaporation, condensation, precipitation, collection
Water goes up as vapor, forms clouds, falls as rain, and gathers again
What process changes liquid water into water vapor?
C1Evaporation
The sun heats water and it rises as a gas
What process changes water vapor into liquid droplets, forming clouds?
C1Condensation
Think of water drops forming on a cold glass
What is the term for water falling from clouds as rain, snow, sleet, or hail?
C1Precipitation
It includes all forms of water falling from the sky
What is the lowest layer of the atmosphere where weather occurs?
C2Troposphere
We live in it; 'tropo' means turning or changing — where weather happens
List the five layers of Earth's atmosphere from lowest to highest.
C2Troposphere, stratosphere, mesosphere, thermosphere, exosphere
The Silly Monkeys Tried Eating — first letters match the layers
Which layer of the atmosphere contains the ozone layer that protects us from UV rays?
C2Stratosphere
It's the second layer up; jets fly in the lower part of it
What process describes how rocks are continuously changed from one type to another over time?
C2The rock cycle
Igneous, sedimentary, and metamorphic rocks can each transform into the other types
What scale measures the hardness of minerals from 1 (softest) to 10 (hardest)?
C2Mohs hardness scale
Talc is 1, diamond is 10
Which rock type forms when melted rock cools and hardens?
C1Igneous
Think fire and magma
Which rock type forms from layers of sediment pressed together?
C1Sedimentary
The word sediment is the clue
Which rock type forms when heat and pressure change an existing rock?
C1Metamorphic
Meta means change
Which trait helps identify a mineral by how hard it is to scratch?
C1Hardness
The Mohs scale measures it
Which rock type is most likely to contain fossils?
C1Sedimentary
Fossils are often buried in layers
Which statement best describes climate?
C1Long-term usual weather
Climate is long-term
What is a weather front?
C1Boundary between air masses
Different air masses meet there
Dark clouds gather and the air pressure drops. What weather is more likely?
C1Rain or a storm
Clouds and falling pressure often signal changing weather
Which Earth layer is liquid metal and helps generate Earth's magnetic field?
C1Outer core
The inner core is solid; the outer core is liquid
A puddle disappears after several warm sunny hours. Which water-cycle process explains this?
C1Evaporation
Liquid water changes into water vapor
Which Earth layer is the hottest and deepest?
C1Inner core
It is solid metal at Earth's center
Which Earth layer is liquid metal and helps create Earth's magnetic field?
C1Outer core
It surrounds the inner core
Put Earth's layers in order from outside to inside.
C1Crust, mantle, outer core, inner core
Start with the thin rocky surface
In the water cycle, what is collection?
C1Water gathering in oceans, lakes, rivers, or groundwater
Collected water is stored before it evaporates again
What is runoff in the water cycle?
C1Water flowing over land into streams, rivers, lakes, or oceans
Rainwater runs over the ground
What is transpiration?
C1Water vapor released from plants
Plants release water vapor through leaves
Which sequence is a common water cycle path?
C1Evaporation, condensation, precipitation, collection
Water rises, forms clouds, falls, then gathers
What is infiltration in the water cycle?
C1Water soaking into the ground
It goes into soil and groundwater
Which kingdom includes multicellular organisms that eat other organisms?
C1Animal kingdom
Humans, dogs, fish, and insects all belong here
Which kingdom includes multicellular organisms that make their own food?
C1Plant kingdom
They use photosynthesis
Which kingdom includes mushrooms, molds, and yeasts?
C1Fungi kingdom
They absorb nutrients from dead or decaying matter
What are the main parts of a plant?
C1Roots, stem, leaves
They go from underground to the top
What is the function of a plant's roots?
C1Absorb water and nutrients from the soil and anchor the plant
They grow underground
What is the function of a plant's stem?
C1Transport water and nutrients between roots and leaves
It acts like a highway for the plant
What is the function of a plant's leaves?
C1Make food through photosynthesis
They capture sunlight
What is photosynthesis?
C1The process by which plants use sunlight, water, and carbon dioxide to make food (glucose) and oxygen
Photo = light, synthesis = putting together
What cell part is called the 'control center' and contains DNA?
C1Nucleus
It directs all cell activities
What rigid outer layer do plant cells have that animal cells do NOT?
C1Cell wall
It gives plant cells their boxy shape
What organelle is called the 'powerhouse of the cell'?
C1Mitochondria
It converts food into energy (ATP)
What organelle in plant cells captures sunlight for photosynthesis?
C1Chloroplast
It contains chlorophyll, which makes plants green
What large organelle in plant cells stores water, nutrients, and waste?
C1Vacuole
Plant cells have one large central one; animal cells have smaller ones
What is an animal with a backbone called?
C1Vertebrate
Fish, amphibians, reptiles, birds, and mammals are all this
What is an animal without a backbone called?
C1Invertebrate
Insects, worms, jellyfish, and spiders are examples
What class of animals is warm-blooded, has hair/fur, and feeds milk to young?
C1Mammals
Humans, dogs, whales, and bats all belong to this class
What class of animals is cold-blooded, has scales, and lays eggs on land?
C1Reptiles
Snakes, lizards, turtles, and crocodiles are examples
What class of animals lives in water as young and on land as adults?
C1Amphibians
Frogs, toads, and salamanders are examples; 'amphi' means both
What are the five kingdoms of life?
C1Monera, Protista, Fungi, Plantae, Animalia
Think: My Pretty Fern Plant Arrived (Monera, Protista, Fungi, Plantae, Animalia)
What part of the cell controls what enters and exits the cell?
C1Cell membrane
It acts like a gatekeeper — it is selectively permeable
What are the five main classes of vertebrates?
C1Fish, Amphibians, Reptiles, Birds, Mammals
Think: FARBM — Fish, Amphibians, Reptiles, Birds, Mammals
What is the natural home or environment where an organism lives?
C1Habitat
A fish's habitat is water; a polar bear's habitat is the Arctic tundra
What is the process called when a caterpillar changes into a butterfly?
C1Metamorphosis
Complete metamorphosis has four stages: egg, larva, pupa, adult
What are the five traditional human senses?
C1Sight, hearing, smell, taste, touch
Eyes, ears, nose, tongue, and skin are the five sense organs
What are the three main macronutrients found in food?
C1Carbohydrates, proteins, and fats
These supply energy (calories) to the body
Which stage often begins the life cycle of a butterfly?
C1Egg
The butterfly lays it on a plant
What is the larva stage of a butterfly commonly called?
C1Caterpillar
It eats leaves and grows quickly
During which butterfly stage does major change happen inside a chrysalis?
C1Pupa
The chrysalis is the clue
Which sequence matches a frog life cycle?
C1Egg, tadpole, adult frog
Young frogs begin as tadpoles
Which animal has complete metamorphosis with egg, larva, pupa, and adult stages?
C2Butterfly
Think caterpillar and chrysalis
Which term names a young insect that resembles the adult but is smaller and lacks full wings?
C2Nymph
Grasshoppers have this kind of young stage
A scientist finds an animal with a backbone, hair, and milk for its young. Which group fits best?
C1Mammal
Hair and milk are mammal clues
An animal has scales, lays eggs on land, and depends on outside heat for body temperature. Which class fits best?
C1Reptile
Scales and land eggs are reptile clues
A plant's leaves are healthy, but water cannot move upward from the roots. Which part is likely damaged?
C1Stem
The stem carries water upward
A plant is wilting because it cannot take in enough water. Which plant part is most directly involved?
C1Roots
This part anchors the plant and absorbs water
What biome is extremely cold with permafrost and almost no trees?
C2Tundra
Found near the Arctic; the ground stays frozen
What biome is the largest land biome, with coniferous (evergreen) forests?
C2Taiga biome
It's south of the tundra; lots of pine and spruce trees
What biome has four seasons and trees that lose their leaves in fall?
C2Temperate deciduous forest
Deciduous means the trees shed their leaves
What biome is dominated by grasses with few trees?
C2Grassland
Prairies in North America and savannas in Africa are examples
What biome receives less than 10 inches of rain per year?
C2Desert
It can be hot or cold, but always very dry
What biome is warm year-round, gets heavy rainfall, and has the most biodiversity?
C2Tropical rainforest
Found near the equator; think Amazon
What are the levels of biological classification from broadest to most specific?
C2Kingdom, Phylum, Class, Order, Family, Genus, Species
King Philip Came Over For Good Spaghetti
What mnemonic helps remember the order of taxonomy?
C2King Philip Came Over For Good Spaghetti
K-P-C-O-F-G-S
What shows the transfer of energy from one organism to another?
C2Food chain
Sun -> grass -> rabbit -> hawk is an example
What type of organism makes its own food from sunlight?
C2Producer
Plants and algae are examples
What type of organism eats other organisms for energy?
C2Consumer
Animals that eat plants or other animals
What type of organism breaks down dead organisms and returns nutrients to the soil?
C2Decomposer
Bacteria, fungi, and worms are examples
What is an animal that eats only plants called?
C2Herbivore
Deer, rabbits, and cows are examples
What is an animal that eats only other animals called?
C2Carnivore
Lions, hawks, and sharks are examples
What is an animal that eats both plants and animals called?
C2Omnivore
Bears, pigs, and humans are examples
What is a community of living things interacting with their nonliving environment?
C2Ecosystem
A pond with its fish, plants, water, and sunlight is an example
What is a network of interconnected food chains in an ecosystem?
C2Food web
It shows that most organisms eat more than one thing
What is a close, long-term relationship between two different species?
C2Symbiosis
It includes mutualism, commensalism, and parasitism
What type of symbiosis benefits BOTH organisms?
C2Mutualism
Bees pollinating flowers is an example — both benefit
What is a trait that helps an organism survive in its environment?
C2Adaptation
A polar bear's thick fur is an example
A camel's long eyelashes and water-saving body are adaptations for which habitat?
C2Desert
Think dry and sandy
A meadow plant feeds a rabbit, and the rabbit feeds a fox. Which organism is the producer?
C2Grass
A producer makes its own food
A polar bear's thick fur and fat layer are adaptations for which kind of habitat?
C2Polar habitat
Think cold, ice, and snow
List the 8 planets in order from the Sun.
C2Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune
My Very Eager Mother Just Served Us Nachos
Which four planets are the rocky (terrestrial) planets?
C2Mercury, Venus, Earth, Mars
The four closest to the Sun are small and rocky
Which four planets are the gas/ice giants?
C2Jupiter, Saturn, Uranus, Neptune
Jupiter and Saturn are gas giants; Uranus and Neptune are ice giants
What is the largest planet in our solar system?
C2Jupiter
It has a famous Great Red Spot
What is the smallest planet in our solar system?
C2Mercury
It's also the closest to the Sun
Which planet is famous for its visible ring system?
C2Saturn
Its rings are made mostly of ice and rock
What type of star is our Sun?
C2Yellow dwarf
It's a medium-sized, medium-temperature star
What is the name of our galaxy?
C2The Milky Way
It's a spiral galaxy
What moon phase occurs when the Moon is between the Earth and Sun (not visible)?
C2New moon
The moon's illuminated side faces away from Earth
What moon phase occurs when the entire face of the Moon is lit?
C2Full moon
Earth is between the Sun and Moon
List the 8 moon phases in order starting from new moon.
C2New, waxing crescent, first quarter, waxing gibbous, full, waning gibbous, third quarter, waning crescent
Waxing = growing, waning = shrinking
What does 'waxing' mean in moon phases?
C2The illuminated portion is growing
Waxing = increasing
What does 'waning' mean in moon phases?
C2The illuminated portion is shrinking
Waning = decreasing
How long does it take Earth to rotate once on its axis?
C224 hours
This rotation causes day and night
How long does it take Earth to orbit (revolve around) the Sun?
C2365.25 days
This is why we have a leap year every 4 years
Which planet is known as the 'Red Planet'?
C2Mars
Its red color comes from iron oxide (rust) on its surface
Which planet is the hottest in our solar system?
C2Venus
Its thick atmosphere traps heat — even though Mercury is closer to the Sun
Where is the asteroid belt located in our solar system?
C2Between Mars and Jupiter
It separates the rocky planets from the gas giants
What is the distance light travels in one year called?
C2Light-year
It's a unit of distance, not time
What is a pattern of stars as seen from Earth called?
C2Constellation
Orion and the Big Dipper are examples
What primarily causes ocean tides on Earth?
C2The gravitational pull of the Moon
The side of Earth closest to the Moon bulges outward
What type of tide occurs when the Sun, Moon, and Earth are aligned (new or full moon)?
C2Spring tide
These are the STRONGEST tides; the Sun and Moon pull together
Which planet has the shortest year (fastest orbit) and almost no atmosphere?
C2Mercury
It's the closest planet to the Sun — just 88 Earth days per orbit
Which planet is the farthest from the Sun and has the strongest winds in the solar system?
C2Neptune
It appears blue due to methane in its atmosphere
During a first quarter moon, how much of the Moon's face appears lit?
C2The right half (50%) is illuminated
'Quarter' refers to one quarter of the way through the lunar cycle, not the amount lit
What simple machine is a bar that pivots on a fulcrum?
C2Lever
A seesaw is an example
What simple machine has a wheel attached to a rod?
C2Wheel and axle
A doorknob and a bicycle wheel are examples
What simple machine uses a wheel with a rope or chain to lift loads?
C2Pulley
A flagpole uses one to raise and lower the flag
What simple machine is a flat surface set at an angle (a ramp)?
C2Inclined plane
A ramp and a hill are examples
What simple machine is like two inclined planes back to back, used to split things?
C2Wedge
An axe and a knife blade are examples
What simple machine is an inclined plane wrapped around a cylinder?
C2Screw
A jar lid and a drill bit are examples
Name the main types of energy.
C2Kinetic, potential, thermal, chemical, electrical, nuclear, light, sound
Energy comes in many forms but is always conserved
What type of energy does a moving object have?
C2Kinetic energy
A rolling ball has this type of energy
What type of energy is stored due to an object's position or condition?
C2Potential energy
A ball held high has gravitational potential energy
What type of energy is related to the temperature of an object?
C2Thermal (heat) energy
The faster particles move, the more of this energy they have
What type of energy is stored in the bonds between atoms?
C2Chemical energy
Food and batteries store this type of energy
What are the four states of matter?
C2Solid, liquid, gas, plasma
The first three are most common on Earth; the fourth is found in stars
In which state of matter are particles packed tightly and vibrate in place?
C2Solid
It has a definite shape and volume
In which state of matter do particles slide past each other?
C2Liquid
It has a definite volume but takes the shape of its container
In which state of matter do particles move freely and fill their container?
C2Gas
It has no definite shape or volume
What is the fourth state of matter found in stars and lightning?
C2Plasma
It's a superheated gas where electrons separate from atoms
What is the phase change from solid to liquid called?
C2Melting
Ice turning to water
What is the phase change from liquid to solid called?
C2Freezing
Water turning to ice
What is the phase change from liquid to gas called?
C2Evaporation
Water turning to steam
What is the phase change from gas to liquid called?
C2Condensation
Water droplets forming on a cold glass
What is the phase change from solid directly to gas called?
C2Sublimation
Dry ice does this — it skips the liquid phase
What force pulls objects toward each other and keeps us on Earth?
C2Gravity
Newton discovered it when an apple fell on his head (legend says)
What force opposes motion between two surfaces in contact?
C2Friction
Rubbing your hands together produces heat because of this force
What is the formula for speed?
C2Speed = distance / time
If you travel 60 miles in 1 hour, your speed is 60 mph
What type of energy flows through wires and powers devices?
C2Electrical energy
It results from the movement of electrons
What type of energy is produced by vibrations traveling through matter?
C2Sound energy
It cannot travel through a vacuum (empty space)
What type of energy travels in waves and can move through empty space?
C2Light (radiant) energy
It comes from the Sun and from lightbulbs
What law states that energy cannot be created or destroyed, only transformed?
C2Law of Conservation of Energy
Energy changes form but the total amount stays the same
A book sits on a table and stays still. Which of Newton's laws explains why it does not move?
C3Newton's First Law (Law of Inertia)
Inertia keeps still things still and moving things moving
When you jump, your feet push down on the ground. What does the ground do?
C3The ground pushes you up with an equal and opposite force
Every action has an equal and opposite reaction
In a Class 1 lever, where is the fulcrum located?
C3Between the effort (force) and the load
A seesaw is a Class 1 lever — the pivot is in the middle
What is Newton's First Law of Motion?
C3Objects keep their motion unless acted on by a force
Also called the Law of Inertia — objects resist changes to their state of motion
What is Newton's Second Law of Motion, expressed as a formula?
C3F = ma (Force = mass × acceleration)
A heavier object requires more force to accelerate at the same rate as a lighter one
What is Newton's Third Law of Motion?
C3For every action, there is an equal and opposite reaction
A rocket launches because the exhaust pushes down and the rocket pushes up equally
What is gravity?
C3A force of attraction between objects with mass
It keeps planets in orbit and makes objects fall to Earth
What is friction?
C3A force that opposes the motion of surfaces sliding against each other
It is why tires grip the road and why your hands get warm when rubbed together
What are the six types of simple machines?
C3Lever, wheel and axle, pulley, inclined plane, wedge, screw
All complex machines are combinations of these six basic types
What happens when light passes from air into glass or water?
C3It bends — this is called refraction
A straw in a glass of water appears bent because of this property
What does sound need in order to travel?
C3A medium
Sound cannot travel in the vacuum of outer space — there is no medium
What is the rule about magnetic poles?
C3Opposite poles attract; like poles repel
North attracts South; North repels North — just like electric charges
What kind of circuit lets electric current flow?
C2Closed circuit
The path must be complete
Why does a bulb turn off when a switch opens the circuit?
C2The path for current is broken.
Open means not complete
Which material is usually a good electrical conductor?
C2Copper
Many wires are made from it
Why is plastic often placed around electrical wires?
C2Plastic is an insulator.
It helps keep current from leaving the wire
What does a battery provide in a simple circuit?
C2Electrical energy
It is the energy source
What happens when light bounces off a mirror?
C2Reflection
Reflect means bounce back
A straw looks bent in a glass of water. Which light behavior explains this?
C2Refraction
Light bends when it moves between air and water
What can a prism separate white light into?
C2Colors of the spectrum
Think rainbow colors
Why does an opaque object make a shadow?
C2It blocks light.
Opaque means light does not pass through
What must an object do to make sound?
C2Vibrate
Feel a speaker or guitar string
Why can sound travel through air?
C2Air particles carry vibrations.
Sound travels as vibrations through matter
A faster vibration usually makes which kind of pitch?
C2Higher pitch
Fast vibrations mean high frequency
Which form of energy is related to heat?
C2Thermal energy
Therm means heat
A lamp changes electrical energy mostly into which useful form?
C2Light energy
What does a lamp give off?
Which surface usually creates more friction for a sliding box?
C2Rough carpet
Rough surfaces resist motion more
Bicycle brakes slow a wheel mostly by using what force?
C2Friction
Brake pads rub against the wheel rim or disc
A wheelbarrow helps lift and move a load. Which simple machine is most obvious in its handles and load point?
C2Lever
The handles move around a pivot near the wheel
An astronaut weighs less on the Moon than on Earth. What best explains the change?
C2The Moon has weaker gravity.
Weight depends on gravity
A dropped ball falls toward Earth. Which force best explains this?
C2Gravity
It pulls objects toward Earth's center
What force gives objects weight on Earth?
C2Gravity
It pulls objects toward Earth's center
What simple machine is a ramp?
C2Inclined plane
It is a flat surface set at an angle
What group of highly reactive metals is in column 1 of the periodic table?
C3Alkali metals
Lithium, sodium, and potassium are examples; they react violently with water
What group of reactive metals is in column 2 of the periodic table?
C3Alkaline earth metals
Beryllium, magnesium, and calcium are examples
What group of highly reactive nonmetals is in column 17?
C3Halogens
Fluorine, chlorine, bromine, and iodine are examples
What group of unreactive gases is in column 18 (the last column)?
C3Noble gases
Helium, neon, and argon are examples; they rarely form compounds
What large group of metals fills the middle of the periodic table (columns 3-12)?
C3Transition metals
Iron, copper, gold, and silver are examples
What positively charged subatomic particle is found in the nucleus?
C3Proton
Its number determines what element an atom is
What subatomic particle has no charge and is found in the nucleus?
C3Neutron
Neutral = no charge
What negatively charged subatomic particle orbits the nucleus?
C3Electron
It's extremely small and moves in 'clouds' around the nucleus
What is the dense center of an atom called?
C3Nucleus
It contains protons and neutrons
What does the atomic number of an element tell you?
C3The number of protons in the nucleus
Each element has a unique number of these
What type of chemical bond forms when one atom gives electrons to another?
C3Ionic bond
It forms between a metal and a nonmetal; table salt (NaCl) is an example
What type of chemical bond forms when atoms share electrons?
C3Covalent bond
It forms between nonmetals; water (H2O) is an example
What type of bond involves a 'sea of electrons' shared among many metal atoms?
C3Metallic bond
This is why metals conduct electricity and are malleable
What type of substance has a pH below 7, tastes sour, and donates hydrogen ions?
C3Acid
Lemon juice and vinegar are examples
What type of substance has a pH above 7, feels slippery, and accepts hydrogen ions?
C3Base
Soap and baking soda are examples
What pH value is considered neutral (neither acid nor base)?
C37
Pure water has this pH
What is the range of the pH scale?
C30 to 14
0 is most acidic, 14 is most basic
What is a substance made of only one type of atom?
C3Element
Gold, oxygen, and carbon are examples
What is a substance made of two or more elements chemically combined?
C3Compound
Water (H2O) and salt (NaCl) are examples
What is a combination of substances that are NOT chemically combined?
C3Mixture
Trail mix and salad are examples; components can be separated physically
What is two or more atoms bonded together called?
C3Molecule
H2O (water) is a molecule made of 2 hydrogen atoms and 1 oxygen atom
What is an atom that has gained or lost electrons (has a charge)?
C3Ion
Positive ions lost electrons; negative ions gained electrons
What is the organized chart of all known elements?
C3Periodic table
Elements are arranged by increasing atomic number
What is a process that changes one set of substances into another?
C3Chemical reaction
Burning wood and rusting iron are examples
What are the starting substances in a chemical reaction called?
C3Reactants
They go on the left side of the arrow in a chemical equation
What are the new substances formed in a chemical reaction called?
C3Products
They go on the right side of the arrow in a chemical equation
What law states that matter cannot be created or destroyed in a chemical reaction?
C3Law of Conservation of Mass
The mass of reactants always equals the mass of products
What type of change alters the form of a substance but NOT its chemical identity?
C3Physical change
Cutting paper, melting ice, and dissolving sugar are examples
What type of change produces a new substance with different properties?
C3Chemical change
Burning, rusting, and cooking are examples
What are the horizontal rows of the periodic table called?
C3Periods
There are 7 of them; elements in each row have the same number of electron shells
What are the vertical columns of the periodic table called?
C3Groups
Elements in the same column share similar chemical properties
Who is considered the father of the periodic table?
C3Dmitri Mendeleev
Russian chemist who arranged elements by atomic mass in 1869
What are elements that have properties of both metals and nonmetals called?
C3Metalloids
Silicon and boron are examples; they form a staircase on the periodic table
What is the chemical symbol for oxygen?
C3O
It has atomic number 8
What is the lightest element on the periodic table?
C3Hydrogen (H)
Atomic number 1; makes up most of the universe
What is the chemical symbol for gold?
C3Au
From the Latin word 'aurum'
What is the chemical symbol for iron?
C3Fe
From the Latin word 'ferrum'
What element is the basis of all organic (living) chemistry?
C3Carbon (C)
Diamond and graphite are both pure forms of this element
What is the chemical symbol for sodium?
C3Na
From the Latin word 'natrium'; it's in table salt (NaCl)
What is the chemical formula for water?
C3H₂O
2 hydrogen atoms bonded to 1 oxygen atom
What is the chemical formula for table salt?
C3NaCl
Sodium + chlorine
What is the chemical formula for carbon dioxide?
C3CO₂
One carbon atom bonded to two oxygen atoms; you exhale it
What gas do we breathe in that is essential for cellular respiration?
C3Oxygen (O₂)
Makes up about 21% of Earth's atmosphere
What type of reaction releases heat energy?
C3Exothermic
When you light a campfire, heat goes OUT. Exo = out, thermic = heat
What type of reaction absorbs heat energy?
C3Endothermic
Photosynthesis and melting ice are examples; 'endo' means in
What substance speeds up a chemical reaction without being consumed?
C3Catalyst
Enzymes are biological catalysts in your body
In a solution, what is the substance that gets dissolved called?
C3Solute
Sugar is the solute when you dissolve it in water
What substance is known as the 'universal solvent'?
C3Water
It dissolves more substances than any other liquid
What is the total number of protons and neutrons in an atom called?
C3Mass number
Protons + neutrons; electrons are too light to count
What are atoms of the same element with different numbers of neutrons called?
C3Isotopes
Iso = same, tope = place. Same spot on the periodic table, different mass
What are the energy levels where electrons orbit the nucleus called?
C3Electron shells
The first shell holds up to 2 electrons, the second up to 8
What are the electrons in the outermost shell of an atom called?
C3Valence electrons
They determine how an atom bonds with other atoms
What are the first five elements of the periodic table in order?
C3Hydrogen (H), Helium (He), Lithium (Li), Beryllium (Be), Boron (B)
Happy Henry Likes Being Bored — first letters match the elements
What are elements 6 through 10 of the periodic table?
C3Carbon (C), Nitrogen (N), Oxygen (O), Fluorine (F), Neon (Ne)
Cowboys Never Order Fish Nuggets — first letters match
What common indicator turns red in acids and blue in bases?
C3Litmus paper
Blue litmus turns red in acid; red litmus turns blue in base
What is the phase change from gas directly to solid called (the reverse of sublimation)?
C3Deposition
Frost forming on a window is an example — water vapor becomes ice without being liquid first
What are elements 11 through 15 of the periodic table?
C3Sodium (Na), Magnesium (Mg), Aluminum (Al), Silicon (Si), Phosphorus (P)
Na and Mg have Latin-based symbols; Si is used in computer chips
What are elements 16 through 20 of the periodic table?
C3Sulfur (S), Chlorine (Cl), Argon (Ar), Potassium (K), Calcium (Ca)
K comes from Latin 'kalium'; Argon is a noble gas; Ca is in your bones
What is formed when an acid and a base react together?
C3A salt and water
HCl + NaOH → NaCl + H₂O is a classic example
What are the three common states of matter?
C2Solid, liquid, and gas
Water can exist in all three: ice (solid), water (liquid), steam (gas)
What are the three particles that make up an atom?
C2Protons, neutrons, and electrons
Protons and neutrons are in the nucleus; electrons orbit around it
What is a pure substance made of only one kind of atom called?
C2An element
Gold, oxygen, and carbon are examples — they cannot be broken down further by chemical means
What is a substance formed when two or more elements are chemically bonded together?
C2A compound
Water (H₂O) and salt (NaCl) are classic examples
How does a mixture differ from a compound?
C2In a mixture, substances are physically combined but not chemically bonded
Trail mix and salad are mixtures — the parts can be separated without a chemical reaction
What does the atomic number of an element on the periodic table tell you?
C2The number of protons in its nucleus
Hydrogen has atomic number 1 because it has 1 proton
What is the difference between a physical change and a chemical change?
C2A physical change alters form but not substance; a chemical change creates a new substance
Cutting paper = physical change; burning paper = chemical change
On the pH scale, what number indicates a neutral substance like pure water?
C27
Below 7 is acidic (lemon juice = 2); above 7 is basic (baking soda = 9)
Water droplets form on the outside of a cold glass. Which state change explains this?
C3Condensation
Water vapor becomes liquid
Copper is used in wiring because it allows electric current to flow. Which property is this?
C3Conductivity
Conductors let current pass
A plastic spoon floats while a metal spoon sinks in water. Which property is being compared?
C2Relative density
Floating and sinking depend on density compared with water
How many major organ systems are in the human body?
C311
From skin to muscles to the brain, they all work together
What organ system includes the skin, hair, and nails?
C3Integumentary system
It's the body's outer covering and largest organ
What organ system provides structure, protection, and produces blood cells?
C3Skeletal system
It includes bones, cartilage, and joints
What organ system allows movement and maintains posture?
C3Muscular system
It includes over 600 muscles in the body
What organ system controls and coordinates body functions using electrical signals?
C3Nervous system
It includes the brain, spinal cord, and nerves
What organ system uses hormones to regulate growth, metabolism, and mood?
C3Endocrine system
Glands like the thyroid, pituitary, and adrenal are part of this system
What organ system pumps blood throughout the body?
C3Cardiovascular (circulatory) system
Heart, arteries, veins, and capillaries
What organ system helps fight disease and drains excess fluid from tissues?
C3Lymphatic system
It includes lymph nodes, the spleen, and the thymus
What organ system brings oxygen into the body and removes carbon dioxide?
C3Respiratory system
Lungs, trachea, and diaphragm are key organs
What organ system breaks down food into nutrients the body can absorb?
C3Digestive system
It includes the mouth, stomach, and intestines
What organ system filters blood and removes liquid waste (urine)?
C3Urinary (excretory) system
The kidneys are the main organs
What organ system is responsible for producing offspring?
C3Reproductive system
It differs between males and females
What are the steps of the scientific method in order?
C3Observation, question, hypothesis, experiment, analysis, conclusion
It starts with observing something and ends with drawing a conclusion
What is a testable prediction or educated guess called?
C3Hypothesis
It's often written as an 'if...then...' statement
In an experiment, what is the variable that the scientist changes on purpose?
C3Independent variable
It's the 'cause' in a cause-and-effect relationship
In an experiment, what is the variable that is measured or observed?
C3Dependent variable
It's the 'effect' — it depends on what you changed
What group in an experiment does NOT receive the experimental treatment?
C3Control group
It provides a baseline for comparison
What is a well-tested explanation for a broad set of observations?
C3Scientific theory
The theory of gravity and cell theory are examples
What is a statement that describes a consistent pattern in nature?
C3Scientific law
It describes WHAT happens, not WHY — like the law of gravity
What is the body's ability to maintain a stable internal environment?
C3Homeostasis
Keeping body temperature at 98.6 degrees F is an example
What is the largest organ of the human body?
C3Skin
It covers your entire body and is part of the integumentary system
What molecule carries the genetic instructions for all living things?
C3DNA
It's shaped like a double helix
What is the basic unit of life?
C3Cell
All living things are made of one or more of these
Which action is a measurement rather than only an observation?
C1Recording that the plant is 12 centimeters tall
Measurements use numbers and units
Which tool is best for measuring the length of a pencil?
C1Ruler
Length is measured with a marked straight edge
Which tool is best for measuring mass?
C1Balance scale
Mass compares how much matter an object has
Which tool measures temperature?
C1Thermometer
It tells how hot or cold something is
Which tool is best for measuring the volume of a liquid?
C2Graduated cylinder
It has marked lines for liquid volume
Which unit best fits the mass of a small apple?
C2grams
Mass commonly uses grams
Why should a student measure more than once in an experiment?
C2To make the result more reliable
Repeated measurements help catch mistakes
A cylinder shows liquid halfway between 40 mL and 50 mL. What volume should you record?
C345 mL
Halfway between 40 and 50 is 45