g) Which element belongs to period 2 and group V.

Here are the solutions to the questions:

g) Which element belongs to period 2 and group V.

• Period 2 indicates that the element has its valence electrons in the second energy shell.
• Group V (or Group 15) indicates that the element has 5 valence electrons.
• The element in Period 2, Group 15 is Nitrogen.

The element is $\boxed{\text{Nitrogen (N)}}$.

h) Write the electronic configuration (S and P notation) of S, V and Z.

• Sulfur (S): Atomic number 16. $$1s^2 2s^2 2p^6 3s^2 3p^4$$
• Vanadium (V): Atomic number 23. $$1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^3$$
• Z: The symbol 'Z' is not a standard chemical symbol for an element. Without further clarification, its electronic configuration cannot be determined.

G) Sodium, magnesium and aluminium are metals in period 3. Write the formulae of their:

• Sodium forms $\text{Na}^+$ ions.
• Magnesium forms $\text{Mg}^{2+}$ ions.
• Aluminium forms $\text{Al}^{3+}$ ions.

a) Hydroxides ($\text{OH}^-$)

• Sodium hydroxide: $\boxed{\text{NaOH}}$
• Magnesium hydroxide: $\boxed{\text{Mg(OH)}_2}$
• Aluminium hydroxide: $\boxed{\text{Al(OH)}_3}$

b) Sulphates ($\text{SO}_4^{2-}$)

• Sodium sulphate: $\boxed{\text{Na}_2\text{SO}_4}$
• Magnesium sulphate: $\boxed{\text{MgSO}_4}$
• Aluminium sulphate: $\boxed{\text{Al}_2(\text{SO}_4)_3}$

c) Carbonates ($\text{CO}_3^{2-}$)

• Sodium carbonate: $\boxed{\text{Na}_2\text{CO}_3}$
• Magnesium carbonate: $\boxed{\text{MgCO}_3}$
• Aluminium carbonate: $\boxed{\text{Al}_2(\text{CO}_3)_3}$

d) Hydrogen carbonates ($\text{HCO}_3^-$)

• Sodium hydrogen carbonate: $\boxed{\text{NaHCO}_3}$
• Magnesium hydrogen carbonate: $\boxed{\text{Mg(HCO}_3)_2}$
• Aluminium hydrogen carbonate: $\boxed{\text{Al(HCO}_3)_3}$

e) Nitrates ($\text{NO}_3^-$)

• Sodium nitrate: $\boxed{\text{NaNO}_3}$
• Magnesium nitrate: $\boxed{\text{Mg(NO}_3)_2}$
• Aluminium nitrate: $\boxed{\text{Al(NO}_3)_3}$

f) Phosphates ($\text{PO}_4^{3-}$)

• Sodium phosphate: $\boxed{\text{Na}_3\text{PO}_4}$
• Magnesium phosphate: $\boxed{\text{Mg}_3(\text{PO}_4)_2}$
• Aluminium phosphate: $\boxed{\text{AlPO}_4}$