Across
1
Second lightest element
4
Gas essential for breathing
6
Group of similar cells
9
Our home planet
Down
2
Basic unit of life
3
Force that attracts objects together
5
Unit of energy
7
Form of thermal energy
8
Molten rock beneath Earth surface
Second lightest element
Gas essential for breathing
Group of similar cells
Our home planet
Basic unit of life
Force that attracts objects together
Unit of energy
Form of thermal energy
Molten rock beneath Earth surface