AP EAPCET 25-Aug-2021 Shift 2 Paper

Velocity of electron in the m h orbit of an atom
is given by v=

2πke2

h

×

Z

n

where,

2πke2

h

is a constant quantity and Z is atomic number.
Hence, speed of electron in first excited state (n=2) is
v=2.188×106×

1

2

(Z=1, for hydrogen atom )
=1.094×106ms−1
Ratio of speed of electron in 1 st excited state to
the speed of light in vacuum =

1.094×106

3×108

=0.364×10−2
=36×10−3