Calculate the orbital period of the electron in the first excited state of hydrogen atom.

Explanation

For first excited state h = 2
Bohr's first postulate :
`(mv^(2))/r=(Kze^(2))/r^(2)" ...(i)"`
`"where K "=1/(4piin_(0))`
Bohr's second postulate :
`mvr=(nh)/(2pi)" ...(2)"`
`T=(2pir)/v" ...(3)"`
From equation (1), (2) and (3)
`T=(4in_(0)^(2)h^(3))/(eta_(e)^(4))h^(3)`
`n = 2` ltbtgt `T=(4in_(0)^(2)h^(3))/(etae^(4))xx2^(3)`
`T=((4xx8.85xx10^(-12))xx(6.63xx10^(-34))^(3)xx8)/(9.11xx10^(-31)xx(1.6xx10^(-19))^(4))`
`T=1.22xx10^(-15)sec.`