Calculate the mass of $3.011\times {10}^{23}$ number of nitrogen atom.

$3.011\times {10}^{23}$ no. of nitrogen atom at mass of nitrogen $=14$g

$1$ mole of nitrogen contains $6.022\times {10}^{23}$ atoms

$14$g will contains $6.022\times {10}^{23}$ atoms

how,

$\frac{14}{6.022\times {10}^{23}}$g contains $1$ atom

$\therefore \left(\frac{14}{6.022\times {10}^{23}}\right)\times 3.011\times {10}^{23}$

$=\frac{14}{2}=7$g of N.