Question

How much time an electron will take for one revolution in second orbit of helium

Answer 1

Answer:

Correct option is

Anh4π 2 mr 2

Explanation:

Time taken for an electron to complete one revolution in Bohr orbit of hydrogen atom is : t=distance/velocity

Distance of Bohr orbit = circumference of Bohr orbit = 2πr

t=

v

2πr

Since mvr=

2π

nh

v=

2πmr

nh

Thus, t=2πr×

nh

2πmr

t=

nh

4π

2

mr

2