Across
1
Hottest planet in solar system
4
Unit of heredity
6
Mass per unit volume
7
Amplified beam of light
8
Second lightest element
13
Icy body with a tail near the sun
Down
2
Biological catalyst
3
Chemical element in table salt
5
Basic unit of life
9
Disturbance that transfers energy
10
Path of a planet around the sun
11
Smallest unit of an element
12
Molten rock beneath Earth surface