ILEARN Science Grade 4 cheat sheet

Matter has mass and takes up space; mass is measured with a balance and volume with a graduated cylinder or ruler.

Weight changes with gravity, but mass stays the same no matter where an object is.

Three common states of matter: solid (fixed shape and volume), liquid (fixed volume, takes container shape), gas (fills any container).

Heating a substance usually makes it expand and can change state: solid to liquid (melting), liquid to gas (evaporation or boiling).

Cooling reverses state changes: gas to liquid (condensation), liquid to solid (freezing).

A physical change alters size, shape, or state but not the material; a chemical change forms a new substance with different properties.

Evidence of a chemical change includes color change, gas bubbles, heat or light given off, and a new smell.

Energy moves as motion, light, sound, heat, or electricity and can transfer between objects but is not created or destroyed.

Simple electric circuits need a power source, wires, and a device; a closed loop lets current flow and an open loop stops it.

Living things share traits: they grow, need energy, respond to surroundings, and reproduce.

Plants make food by photosynthesis using sunlight, water, and carbon dioxide, and release oxygen.

Food chains show energy flow: producers (plants) to consumers (animals) to decomposers (fungi, bacteria).

A food web joins several food chains; removing one organism can affect many others.

Structures have functions: roots absorb water, stems support and transport, leaves capture sunlight.

Animal adaptations are body parts or behaviors that help survival in a habitat, such as thick fur or migration.

Metamorphosis is a body change during life cycles: complete (egg, larva, pupa, adult) or incomplete (egg, nymph, adult).

Inherited traits come from parents (eye color, fur pattern); learned behaviors come from experience (riding a bike).

Ecosystems include living organisms and nonliving parts such as soil, water, air, and sunlight.

Earth rotates on its axis once about every 24 hours, causing day and night.

Earth revolves around the Sun once about every 365 days, causing the seasons along with the tilt of Earth's axis.

The Sun appears to rise in the east and set in the west because Earth spins west to east.

The Moon orbits Earth about every month and shows phases (new, crescent, quarter, gibbous, full) as its lit side is seen from different angles.

The water cycle repeats: evaporation, condensation into clouds, precipitation, and collection in bodies of water.

Weather is day-to-day conditions; climate is the usual weather pattern of a place over a long time.

Earth's layers are the crust, mantle, and core; the crust is the thin outer rocky layer.

Fossils in rock layers show that organisms lived long ago; deeper layers are usually older.

Natural resources can be renewable (sunlight, wind, water) or nonrenewable (coal, oil, minerals).