Across
1
Absolute temperature scale unit
4
Particle of light
5
Unit of energy
7
Curved glass that refracts light
10
Unit of electric potential
11
Mass per unit volume
Down
2
Gas essential for breathing
3
Blocking of light by a celestial body
4
Glass that splits light into spectrum
6
Magnetic metallic element
8
Tissue that contracts for movement
9
Nerve cell in the brain