Calculate the impact parameter of 5.0 MeV `alpha`-particle scattered by `10^(@)` when it approaches a gold nuclcus (Z = 79).

Explanation

`Z_(1)=2,z_(2)=z=79`
Impact parameter, `b=(Ze^(2)cot(theta//2))/(4pi epsilon_(0)((1)/(2)mv^(2)))`
Here `theta=10^(@),E=(1)/(2)mv^(2)=5.0xx1.6xx10^(-13)J`
`(1)/(4pi epsilon_(0))=9xx10^(-9)Nm^(2)C^(-2)`
`:.b=(79xx(1.6xx10^(-19))^(2)cot5^(0)xx9xx10^(9))/(5.0xx1.6xx10^(-13))`
`=2.6xx10^(-13)m`