3.
If I have 0.5 moles of Magnesium then how many atoms of magnesium is
present?

1 mole of MgO contains Avogadro's number of molecules which is 6.023×10^23

molecules.

0.5 mole of MgO will contain 0.5×6.023×10^23

=3.0115×10^23 molecules

conduction is the transfer of thermal energy (heat in transfer) due to collisions between the molecules in the object. collisions between adjacent atoms and molecules transfer kinetic energy from the warmer to the cooler object. the objects must be in physical contact.