Question

The diameter of zinc atom is$2.6 \AA$. Calculate (a) radius of zinc atom in pm and (b) number of atoms present in a length of 1.6 cm if the zinc atoms are arranged side by side lengthwise.

Answer 1

"From the given,

Radius of zinc atom $= 2.6 \AA$

Length = 1.6 cm

The segment joining the centre of a circle to a point on the circle is called radius.

Formula:$\quad \frac { 1 }{ 2 } \quad \times \quad Diameter$

=$\quad \frac { 1 }{ 2 } \quad \times \quad 2\quad =\quad 1.3\AA \quad =\quad 1.3\quad \times \quad { 10 }^{ -10 }\quad m$

=$\quad 130\quad \times \quad { 10 }^{ -12 }\quad pm$

Given length = 1.6 cm

=$\quad 1.6\quad \times \quad { 10 }^{ -2 }\quad m$

Diameter of one atom =$\quad 2.6\AA \quad =\quad 2.6\quad \times \quad { 10 }^{ -10 }\quad m$

Number of atoms present along the length =$\quad \frac { 1.6\quad \times \quad { 10 }^{ -2 } }{ 2.6\quad \times \quad { 10 }^{ -10 } }$

=$\quad 6.154\quad \times { \quad 10 }^{ 7 }$"