The periodic time of radiation is $4 \times 10^{-10} \ s$. Find the wavelength,wave number,and frequency.

• A
  $\nu = 2.5 \times 10^{9} \ Hz, \lambda = 0.12 \ m, \bar{\nu} = 8.33 \ m^{-1}$
• B
  $\nu = 2.5 \times 10^{8} \ Hz, \lambda = 0.12 \ m, \bar{\nu} = 8.33 \ m^{-1}$
• C
  $\nu = 2.5 \times 10^{9} \ Hz, \lambda = 0.12 \ m, \bar{\nu} = 8.33 \ cm^{-1}$
• D
  $\nu = 2.5 \times 10^{10} \ Hz, \lambda = 0.12 \ m, \bar{\nu} = 8.33 \ m^{-1}$