Question

What quantity in moles of potassium atoms do you have if you have 5.70 × 10²² atoms of potassium. (The mass of one mole of potassium is 39.10 g.)

Answer 1

$1\space mole\equiv6.02×10^{23}$ From Avogadro's number

$x\space mole \equiv5.7×10^{22}$

$X=\frac{5.7×10^{22}}{6.02×10^{23}}×1mole=9.468×10^{-2}$