Science

Matter exists mainly as a solid, liquid, or gas. Solids keep their shape, liquids take the shape of their container, and gases spread out to fill any space.

Ice → water → steam is the same water, three different states.

Water travels in a cycle: the sun heats oceans so water evaporates into vapor, the vapor cools to form clouds through condensation, and falls back as precipitation.

Evaporate up, condense into clouds, precipitate back down.

Most plants begin as a seed, which sprouts into a seedling, grows into a mature plant that produces flowers, which make new seeds.

Seed → seedling → adult plant → flowers → new seeds.

A simple machine makes work easier by changing the size or direction of a force, like a lever, a wheel and axle, or an inclined plane (ramp).

A ramp lets you push a heavy box up slowly instead of lifting it straight up.