A H-atom moving with speed v makes a head on collisioon with a H-atom at rest . Both atoms are in ground state. The minimum value of velocity v for which one of the atom may excite is `(1.25 nxx10^(4))` m/s Find value of x.

Options

A. `6.25xx10^(4)ms^(-1)`
B. `8xx10^(4)ms^(-1)`
C. `7.25xx10^(4)ms^(-1)`
D. `13.6xx10^(4)ms^(-1)`

Answer

A

Explanation

Minimum 10.2 eV energy is required to exctie a hydrogen atom. In perfectly inelastic collison maximum energy is lost.
`:. "energy los" =(1)/(2)(2m)((v)/(2))^(2)=10.2xx1.6xx10^(-19)`
`" " (1)/(4)mv^(2)=1.632xx10^(-18)`
`:. "velocity"vsqrt((1.632xx4xx10^(-18))/(1.67xx10^(-27)))=6.25xx10^(4)ms^(-1)`