Which pair must represent atoms of the same element?

How many liters of oxygen gas, at standard temperature and pressure, will react with 35.8 grams of iron metal? 4 fe (s) + 3 o₂ (g) → 2 fe₂o₃ (s)

What causes different colors to appear in the sky? the absorption of light by air molecules the reflection of light by bodies of water the greenhouse effect in earth's atmosphere the scattering and reflection of light by dust particles

Nuclear decay is the spontaneous decay of one element into a. an x-ray b. a ray of light c. another element