# The diameter of zinc atom is 2.6 Å. The total number of atoms present in a length of 1.6 cm if the zinc atoms are arranged side by side length-wise are Option 1) $6.15\times10^{9}$ Option 2) $2.6\times10^{9}$ Option 3) $2.6\times10^{8}$ Option 4) $6.15\times10^{7}$

As we discussed in concept

The distance from the centre of the nucleus to the outermost shell containing the electrons is called atomic radius.It can be measured by the spectroscopic method and by x-ray diffraction or electron diffraction techniques.

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Diameter = $2.6\times10^{-10}m$

Length = $1.6\times10^{-2}m$

No. of zinc atoms = $\frac{1.6\times 10^{-2}}{2.6\times 10^{-10}}\:=\:6.15\times 10^{7}$

Option 1)

$6.15\times10^{9}$

This option is incorrect.

Option 2)

$2.6\times10^{9}$

This option is incorrect.

Option 3)

$2.6\times10^{8}$

This option is incorrect.

Option 4)

$6.15\times10^{7}$

This option is correct.

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