Earth’s helps protect life from ultraviolet radiation. Earth’s atmosphere is mostly made up of the gases and .

There is some evidence to suggest that Mars once had liquid , though now it may be trapped as .

the correct answer is b

black

lasagna

lunch

math

hydrogen is a compound or a single element and a element is a pure substence that cannot be separated into simpler subtances

clorine is a compound its a chemical substance that forms when two or more different elements combine

so both hydrogen and clorine are compounds

this might