1.
huge group of stars, planets and celestial objects
2.
building blocks of matter
4.
2 or more atoms that are connected to make a substance
5.
how far light travels in a year
6.
large celestial object that travels around a star
7.
the removal of trees from forests
8.
the variety of life in a habitat or ecosystem
9.
what gives things the power to move, change, or work
10.
the force that pushes electricity through a circuit
11.
a young star still forming
12.
a force that pulls objects together
13.
the average weather conditions in a certain place
14.
simplest form of matter
15.
a community of living and non-living things
16.
a push or pull that can cause an object to change its motion
17.
the amount of matter in an object
