Frequency of a light wave
(υ) =

1

Time‌period

=

1

2.0×10−10

= 5 × 109s−1
Wavelength of light wave (λ) =

c

υ

=

3×108

5×109

= 6.0 × 10−2m
Wavenumber of light wave (

−

v

) =

1

λ

=

1

6.0×10−2

= 16.6 m−1
Therefore, wavelength, frequency and wavenumber of the light wave are 6.0 × 10–2 m, 5 × 109s–1 and 16.6 m–1 respectively.