Calculate the wavelength of light with a frequency of 1.89 x 1018 hz.

Which sentence from "Black Hole Beginnings" contains a cause-and-effect relationship?
More matter mounts up on the outside, increasing the pressure on the inside.
Instead it is a dramatic melding, or blending, of atoms, called nuclear fusion.
Each atom has its own tiny center, or nucleus.
Surrounding each nucleus is an electrical force field..

It is 4.92 e-4 sorry if i am wrong