Question

In the Gold foil experiment, 1% of the $\alpha$ -particles were found to deflect at angles > 50⁰. If one mole of $\alpha$-particles were bombarded on the gold foil, calculate the number of $\alpha$-particles that would deflect at angles less than 50⁰.

Answer 1

Calculation of No. of $\alpha$- particles deflected at an angle less than 50^o :

Percentage (%) of $\alpha$-particles deflected at an angle more than 50^o = 1%

Percentage (%) of $\alpha$- particles deflected at an angle less than 50^o = 100 - 1 = 99%

Moles of $\alpha$- particles that bombarded the given gold foil = $1\mathrm{mol}\mathrm{or}6.023\mathrm{X}{10}^{23}$

No. of $\alpha$- particles deflected at an angle less than 50^o =$\frac{6.023\mathrm{X}{10}^{23}\mathrm{X}99}{100}=5.96\mathrm{X}{10}^{23}$

Therefore $5.96\mathrm{X}{10}^{23}$$\alpha$- particles deflected at an angle less than 50^o