Given a mole each for iron and magnesium, the number of atoms of each element is equal. Iron has a greater mass due to its greater molecular weight. The correct statement among the choices is D.
Each element or compound has a molar mass, which is calculated by multiplying the atomic mass of each element by the amount of atoms of that element, and summing the results of each element. The molar mass is measured in g/mol. So you divide the mass in grams by the molar mass to get the amount of moles.
Example:
There are 5g of water.
Calculate the amount of moles.
The water's formula is H2O, so the molar mass of it is

g/mol.
The amount of moles is:
5g ÷ 18g/mol ~ 0.28mol
Answer:
<h2>1.89 atm</h2>
Explanation:
The new volume can be found by using the formula for Boyle's law which is

Since we are finding the new volume

From the question we have

We have the final answer as
<h3>1.89 atm</h3>
Hope this helps you