# What is the mass of electron if the charge of electron and the ratio of charge to mass are 1.6*10^(-19)"C" and 1.76*10^8"C/g" , respectively?

$m = 9.1 \times {10}^{-} 28 g$
$1.76 \times {10}^{8} = \frac{1.6 \times {10}^{-} 19}{m}$
so $m = \frac{1.6 \times {10}^{-} 19}{1.76 \times {10}^{8}} = 9.1 \times {10}^{-} 28 g$