0.25 mole of c has the same number of atoms as 0.25 mole of hg. true or false?

True.

Because mole is a fixed amount. It is 6.022 * 10^ 23.

So, both 0.25 mole of C and 0.25 mole of Hg have 6.022 * 10^23 atoms, each.

Saying mole is analog to say a dozen: a dozen is 12 and a mol is 6.022 * 10^23.

Electrical charges of ionic bonds