12.4 g of phosphorus reacts with 9.6 g of oxygen. Which of the following chemical equation represents this reaction?
[Relative atomic mass: P, 31; 0, 16]
A P + O2 + PO2
B 2 P + O2 + 2 PO
C 3P +2 02 → P304
D 4P +3 02 → 2 P203

D 4P +3O₂ → 2 P₂O₃

Explanation:

In this problem, we need to convert the mass of phosphorus and oxygen to moles trying to find the ratio of reaction (The moles of P that reacts per mole of O₂):

Moles P:

12.4g P * (1mol P / 31g) = 0.4 moles

Moles O₂:

9.6g * (1mol / 32g) = 0.3 moles

The ratio of reaction is:

0.4 mol / 0.3 mol = 1.33 = 4 moles of P / 3 moles of O₂

That means 4 moles of P react with 3 moles of O₂ and the reaction that represents this ratio is:

answer:

the answer is 6 valence electrons.

explanation:

valence is the # of electrons on the outer most shell of an atom.

oxygen has 6.

although, the valency of oxygen is 2, because it only needs to make 2 covalent bonds, or gain 2 electrons, to achieve the stable octet configuration of a noble gas.

that's it!

if you need further assistance, let me know: )

~ trueboss72

answer:

technetium is the most reactive. this is followed by silver. the least reactive out of these three elements is strontium.