How to find the group number of f block elements​

How many liters of hydrogen gas will be produced at stp from the reaction of 7.179×10^23 atoms of magnesium with 54.219g of phosphoric acid (h3po4) the equation is 3mg + 2h3(> mg(po4)2+3h2

Predict whether the changes in enthalpy, entropy, and free energy will be positive or negative for the boiling of water, and explain your predictions. how does temperature affect the spontaneity of this process?

If two atoms are bonded to a central atom with no lone pairs,how will they be arranged