Answer: [tex]3.903\times 10^{23}[/tex]
Explanation:
Given
Mass of magnesium is [tex]m=15.75\ gm[/tex]
The molar mass of magnesium [tex]M=24.3\ g/mol[/tex]
No of moles in 15.75 g of magnesium is
[tex]\Rightarrow n=\dfrac{15.75}{24.3}\\\\\Rightarrow n=0.648\ \text{moles}[/tex]
1 mole contains [tex]6.022\times 10^{23}[/tex] atoms
So, 0.648 moles contain [tex]0.648\times 6.022\times 10^{23}[/tex]
[tex]=3.903\times 10^{23}\ \text{atoms}[/tex]
