Across
1
Preserved remains of ancient life
3
Reddish electrical conductor
4
Unit of heredity
6
Path of a planet around the sun
7
Blocking of light by a celestial body
8
Chemical element in table salt
Down
1
Push or pull on an object
2
Curved glass that refracts light
4
Precious yellow metallic element
5
Magnetic metallic element
9
Nerve cell in the brain