Question

Medical x rays are taken with electromagnetic waves having a wavelength around .1 nm. What are the frequency, period, and wave number of such waves?

ok I got the frequency as 3 * 10^18 Hz and the wave number as 6.3 *10^10 rad/m but I can't seem to remember how to get period.

Answer 1

period = 1/frequency

Answer 2

frequency = speed/wavelength = c/L
= (3*10^8 m/s) / .1*10^-9 m
= (3/.1) * 10^17 s
= 3 * 10^18 Hz check

k = 2 pi/L
k = 2 pi / (.1*10^-9)
= 6.28 * 10^10 check