Across
1
Gas essential for breathing
2
Curved glass that refracts light
6
Positive particle in nucleus
Down
2
Amplified beam of light
3
Mass per unit volume
4
The Red Planet
5
Precious yellow metallic element
7
Push or pull on an object
Gas essential for breathing
Curved glass that refracts light
Positive particle in nucleus
Amplified beam of light
Mass per unit volume
The Red Planet
Precious yellow metallic element
Push or pull on an object