Aray in the emission spectrum has a wavelength of 3.10 x 1014 meters. given that the speed of light is 2.998 x 108 m/s, what is the frequency of the ray? a. 0.967 x 10-6 hz b. 9.2938 x 10-7 hz c. 0.967 x 10-5 hz d. 9.2938 x 107 hz

Frequency has units of Hz which is s^-1

m/s * (1/m) = 1/s
"E" stands for the magnitude x10^
2.998 E8   m/s * ( 1 wave / 3.10 E14 m) = 9.67 E-7

frequency = 9.67 x 10^-7 Hz
move the decimal place to the left and you're looking at solution A.

The problem here is that according to aufbau principle before 3d orbital 4s subshell comes.after filling 3p orbital with electrons you have 4 electrons left, you place two in 4s with opposite spin and the other two in 3d in any of its two orbitals of total five orbitals with the same spin.