The Atoms in 191 g of calcium is [tex]\bold{2.869 \times 10^{24}}[/tex] atoms Ca
Explanation:
To calculate the number of atoms of Ca in 191 g Ca.
Convert the given mass of calcium to moles of calcium,
Using its molar mass (referring to a periodic table, this is 40.08gmol):
191g Ca× [tex]\left(\frac{1\ \mathrm{mol} \mathrm{Ca}}{40.08\ \mathrm{g} \mathrm{Ca}}\right)[/tex]=4.765 mol Ca
Using Avogadro's number, [tex]6.022 \times 10^{23}[/tex] particles mol, calculate the number of atoms present
[tex]4.765 \ mol\ Ca\times \left(\frac{6.022 \times 10^{23}}{1 \mathrm\ {mol} \mathrm\ {Ca}}\right)= 2.869 \times 10^{24} atoms\ Ca[/tex]
