Find out the number of waves made by a bohr electron in one complete revolution in its third orbit.

Explanation

` r_n "for" H = r_1 xx n^2`
` r_3" for " H = 0. 529 xx 9 xx 10^(-8) cm 9:. R_2 = 0. 529 Å `
Also ` u -n = u_1/n`
` :. U_3 = ( 2 . 19 xx 10^8)/3 cm sec^(-1)`
` 9 :. U_1 = 2. 19 xx 10^8 cm sec^(-1)`
`:.` No. of waves in one round ` = (2 pi r_3)/ ( lambda) = ( 2 pu r_3)/( h//mu_3)`
` = ( 2 pi r_3) xx u_3 xx (m)/h`
` = (9 2 xx 22 xx 0. 529 xx 9 xx 10^(-8) xx 2. 19 xx 10^8 xx 9. 108 xx 10^(-28))/( 7 xx 3 xx 6.62 xx 10^(-27))`
` =3` .