Question

What is the mass of one atom of $C-12$ in grams?

• A. 1.992$\times {10}^{-23}$ gm
• B. 1.989$\times {10}^{-23}$ gm
• C. 1.892$\times {10}^{-23}$ gm
• D. 1.965$\times {10}^{-23}$ gm

Answer 1

The correct option is A 1.992$\times {10}^{-23}$ gm

Mass of $1$ mole = $12gm$

Mass of $6.022\times {10}^{23}atom=12gm$

mass of $1$ atom = $\frac{12}{6.023\times {10}^{23}}=1.993\times {10}^{-23}gm$