How many moles are equal to 9.03x10 24 atoms of mercury

Based on Avogadro's concept, one mole of any substance contains Avogadro's number of atoms.

This means that one mole of mercury contains 6.022 * 10^23 atoms. To know how many moles of mercury contain 9.03 *10^24 atoms, all you have to do is cross multiplication as follows:
1 mole > 6.022 * 10^23 atoms
?? moles > 9.03 * 10^24 atoms

number of moles = (9.03*10^24 * 1) / (6.022*10^23) = 14.995 moles

As we know that mole is unit of measuring amount or number of atoms, it is an absolute number. One mole is equal to 6.022 X 10^23 atoms. In given problem, we are given 9.03 X 10^24 atoms of mercury. So, number of moles in the given mercury sample will be (9.03 X 10^24)/(6.022 X 10^23). That is, 14.995 ~ 15 moles

Exothermic,  physical change after it is already baked