Can anyone explain to me how I solve 3x10^8 / 3.82x10^-7 I know the answer due to referring to the key but I'm not sure how they got it. Answer was 7.85x10^14

You have to do this on a calculator. So when you put it in the calculator you will get 7.85x10^14.

3x10^8 is the speed of light. 3.82x10^-7 is the number in the question.

You can solve it like this

3x10^8

3.82x10^7                  

But you would do this on a calculator.

where's the diagram?

"among the transition metal elements, manganese and zinc have a slight lowering of electronegativities. the reason behind this is that the nuclear charges of these elements are slightly weaker than the other transition metal elements due to the way their valence electrons are filled up. both manganese and zinc have their valence electrons filled up to the 4th shell with 1 pair of electrons (4s2) completely occupying it. although the electrons in the 3rd shell (3d) are yet to be paired since the outer most shell is filled up, the ability of the nucleus to attract electrons is lessened. hence,   the electronegativity (or the ability to attract electrons) is lessened."