Every mole is 22.4 L at STP
The Selenium is the element that is likely to be the most brittle
Answer:
It is reactive because it has to gain an electron to have a full outermost energy level.
Explanation:
The electron configuration of oxygen is 1s2,2s2 2p4.
Oxygen is in group six in the periodic table so it has six electrons in its valence shell. This means that it needs to gain two electrons to obey the octet rule and have a full outer shell of electrons (eight).
Answer:

Explanation:
You must calculate the moles of P₄O₁₀, convert to moles of P₂O₅, then convert to molecules of P₂O₅.
1. Moles of P₄O₁₀

2. Moles of P₂O₅
P₄O₁₀ ⟶ 2P₂O₅
The molar ratio is 2 mol P₂O₅:1 mol P₄O₁₀
3. Molecules of P₂O₅
