Across
1
Center of an atom or cell
4
Smallest unit of an element
Down
2
Compound containing oxygen
3
Gas essential for breathing
5
Tissue that contracts for movement
6
Second lightest element
7
Form of thermal energy
8
Amplified beam of light
Center of an atom or cell
Smallest unit of an element
Compound containing oxygen
Gas essential for breathing
Tissue that contracts for movement
Second lightest element
Form of thermal energy
Amplified beam of light