Across
1
Group of similar cells
5
Basic unit of life
6
Form of thermal energy
8
Smallest unit of an element
Down
2
Second lightest element
3
Biological catalyst
4
Ball of burning gas in space
7
Path of a planet around the sun
Group of similar cells
Basic unit of life
Form of thermal energy
Smallest unit of an element
Second lightest element
Biological catalyst
Ball of burning gas in space
Path of a planet around the sun