Answer
$1.732\times10^{23}\ atoms\ Cr $
Work Step by Step
1. Use the molar mass of chromium and Avogadro's number as conversion factors in order to determine the number of atoms of chromium.
2. $14.955 g\ Cr \times\frac{1\ mol\ Cr}{51.996\ g\ Cr}\times\frac{6.022\times10^{23}}{1\ mol\ Cr}= 1.732\times10^{23}\ atoms\ Cr $