Thus problem is providing us with the mass of iron (III) oxide as 12.4 g so the moles are required and found to be 0.0776 mol after the calculations:
<h3>Mole-mass relationships:</h3>
In chemistry, we use mole-mass relationships in order to calculate grams from moles and vice versa. In this case, since we are given the mass of iron (III) oxide as 12.4 g one can calculate the moles by firstly quantifying its molar mass:

Then, we prepare a conversion factor in order to cancel out the grams and thus, get moles:

Learn more about mole-mass relationships: brainly.com/question/18311376
A is the answer, and put the choices
evaporation. When a substance undergoes a change of matter from a solid to gas, it is the process of evaporation.
Hope this helps
Answer:
d.have a mass of 1 amu..
Explanation:
Does not match a as the answer for a is electrons B.electron circle around the nucleus because neutrons are inside the nucleus.C.proton and neutrons make the nucleus so the only answer left is .d .which is correct
Answer:
666.5
Explanation:
Multiply 2.15 and 3.1 to get 6.665.
6.665×100≈666.5
Multiply 6.665 and 100 to get 666.5.
666.5