Elements occur naturally in different forms called isotopes. These are the same atoms with the same number of protons but has different number of neutrons. Almost all elements exist in nature as such. The amounts of these isotopes are expressed in terms of percent abundances and since it is in a percentage units, the sum of all the abundances should equate to 100 percent or else the calculation is wrong. This is not true onlt for magnesiun but with all of the elements. The atomic mass of these elements also depends on the percent abundances of the isotopes since it is a weighted average value of the individual masses of the isotopes.
<u>Answer:</u> The number of phosphorus atoms in given amount of copper(II) phosphate is 
<u>Explanation:</u>
We are given:
Moles of copper(II) phosphate 
= 7.00 mol
1 mole of copper(II) phosphate contains 3 moles of copper, 2 moles of phosphorus and 8 moles of oxygen atoms
Moles of phosphorus in copper(II) phosphate = 
According to the mole concept:
1 mole of a compound contains 
number of particles
So, 7.00 moles of copper(II) phosphate will contain = 
number of phosphorus atoms.
Hence, the number of phosphorus atoms in given amount of copper(II) phosphate is
An electron because that is the only part able to be lost or gained without nuclear action needed
