We know because of DNA testing in general.
A tall, horizontally subdivided or packed container for fractional distillation in which vapor passes upward and condensing liquid flows downward. The vapor becomes progressively enriched in more volatile components as it ascends, and the less volatile components become concentrated in the descending liquid, which can be drawn off.
So scientist around the world can share there info without having to convert and doing extra work.
Molar mass:
O2 = 16 x 2 = 32.0 g/mol Mg = 24 g/mol
<span>2 Mg(s) + O2(g) --->2 MgO(s)
</span>
2 x 24.0 g Mg -------------> 32 g O2
5.00 g Mg -----------------> ( mass of O2)
mass of O2 = 5.00 x 32 / 2 x 24.0
mass of O2 = 160 / 48
= 3.33 g of O2
hope this helps!
Answer: Planet A: 76% Nitrogen, 23% Oxygen, 1% Other
Explanation: Hope this helps!
