An electron in a hydrogen atom in its ground state absorbs 1.5 times as much energy as the minimum require for it to escape from the atom. What is the velocity of the emitted electron?

Options

A. `1.54xx10^(6)m//s`
B. `1.54xx10^(8)m//s`
C. `1.54 xx 10^(3)m//s`
D. `1.54xx10^(4)m//s`

Answer

A

Explanation

Energy absorbed `=13.6 xx 1.5=20.4eV` of this 6.8 eV is converted to K.E.
`6.8 eV rArr 6.8 xx 1.6 xx 10^(-19)J, 6.8 xx 1.6 xx 10^(-19) =K.E. rArr ((1)/(2))mv^(2)`
`v= sqrt((2KE)/(m)) = sqrt((2xx1.088xx10^(-18))/(9.1xx10^(-31)))=1.54xx10^(6)m//s`