What will be the mass of one `.^(12)C` atom in `g`?

Explanation

The mass of a carbon -12atom was determined by a mass spectrometer and found to be equal to 1.992648xx`10^(-23)g` is is known that 1 mole of C-12 atom weighing 12 g contains `N_(A)` number of atoms Thus.
1 mole of C-12 atoms `=12g= 6.022xx10^(23)` atoms
`rArr6.022xx10^(23)` atoms of C-12 have mass =12g
`therefore` 1 atom of C-12 will have mass `=(12)/(6.022xx10^(23))g`
`=1.992648xx10^(-23)g=1.99xx10^(-23)g`