Question

Calculate the actual mass of 1) an atom of hydrogen 2) an atom of silver 3) 0.25 gram atom of calcium

Answer 1

$$\begin{gathered} a.1moleofhydrogen=1.008g \\ 1mole=6.022\times {10}^{23}atomsofhydrogen \\ 1atomofhydrogen=\frac{1.008}{6.022\times {10}^{23}}=1.67\times {10}^{-24}g \\ b.1moleofsilver=108g \\ 1mole=6.022\times {10}^{23}atomsofsilver \\ 1atomofsilver=\frac{108}{6.022\times {10}^{23}}=17.93\times {10}^{-23}g \\ c.1moleofcalcium=40g \\ 1mole=6.022\times {10}^{23}atoms \\ 0.25gramatomofcalcium=\frac{40}{6.022\times {10}^{23}}\times 0.25=1.66\times {10}^{-23}g \end{gathered}$$