Why is Cobalt (Co) placed before Nickel (Ni) on the Periodic Table of the Elements even though it has a higher average atomic mass than nickel?

Cobalt has 27 protons while Nickel has 28.

Explanation:

atomic mass does have to do with protons and neutrons, but its not what places the elements

make flash cards, or have a 'study date' with your friends or something! always works for me! : d

answer; approx,300,000 ;