2. Convert 6.578 x 1023 atoms of magnesium to moles.
6.578 x 1023 atoms x
mol
atoms

1.092 moles of Mg

Explanation:

Avogadro's number is a constant that define the number of particles (Such as atoms, molecules, electrons, ions) that you have in 1 mole. That means in 1 mole you have 6.022x10²³ of the particle in question.

If you have 6.578x10²³ atoms of Mg -and 1 mole of Mg contains 6.022x10²³ atoms of Mg-:

6.578x10²³ atoms of Mg × (1 mole Mg / 6.022x10²³ atoms of Mg) =

percent abundance for cu-63 can be shown as:

63 x + 65 (1-x) = 62.9296

65 - 62.9296 = 2 x

x = 1.035

thus, percent abundance for cu-63 is 1.035

percent abundance for cu-65 can be shown as:

63 x + 65 (1-x) = 64.9278

65 - 64.9278 = 2 x

x = 0.0361

thus, percent abundance for cu-63 is 0.0361

the mass spectrum of cu-63 showing the intense peak as, this isotope is found in nature more abundantly around 92.38 % in comparison to cu-65 which is found 62.58 % naturally