What are points a and b? what does this diagram show? whats point c?

a is Cation

b is delocalised electrons

This diagram is a representation of physical property in metal called Malleable

c is the electrostatic force

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.

m=9

step-by-step explanation: