Answer:
20 moles
Explanation:
The important thing to realize here is that you're working under STP conditions, which implies that you can use the molar volume of a gas at STP to find how many moles of helium will occupy that volume.
Answer: option D.
The total number of atoms of each element on both sides of the
equation must be the same.
Explanation:
Since protons are postive and neutrons are neutral. Then it is postive.