Across
1
Reddish electrical conductor
4
Element found in all living things
5
The Red Planet
7
Gas essential for breathing
8
Blocking of light by a celestial body
Down
2
Center of an atom or cell
3
Icy body with a tail near the sun
6
Measure of matter in an object
9
Unit of energy
10
Particle of light
11
Smallest unit of an element
12
Basic unit of life
13
Path of a planet around the sun
14
Push or pull on an object