structures that help organisms survive in their surroundings

the air that surrounds the Earth

the smallest particle of a substance that has all the properties of an element

an imaginary line that passes from the North Pole to the South Pole through Earth's center

the up-and-down line at the left side of a graph or the side-to-side line at the bottom of a graph

an animal that eats other animals

a physical change that occurs when a solid, liquid, or gas turns into another form

a change that produces a new substance

populations of different kinds of organisms that live in the same place at the same time

a substance whose molecules contain atoms of different elements

the process of changing from a gas to a liquid

a group of stars that ancient people thought formed a picture in the night sky

an organism that gets energy by eating other organisms

an organism that gets energy by feeding on dead materials and wastes

the amount of mass in a known volume of an object or substance

the process on which materials eroded by water, wind, or ice are dropped in a new place

a shaking of Earth's crust caused by rock slabs moving against each other deep below the Earth's crust

all the living and nonliving that interact with each other in an environment

a pure substance made of only one kind of atom

the ability to do work

a diagram that shows the amount of energy passed on at each level of a food chain

a change of energy from one form to another or the movement of energy from one object to another

the surroundings that an organism lives in

an imaginary line around the middle of the Earth, halfway between the two poles