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 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 Na^+ ions. Magnesium forms Mg^2+ ions. Aluminium forms Al^3+ ions. a) Hydroxides (OH^-) Sodium hydroxide: NaOH Magnesium hydroxide: Mg(OH)_2 Aluminium hydroxide: Al(OH)_3 b) Sulphates (SO_4^2-) Sodium sulphate: Na_2SO_4 Magnesium sulphate: MgSO_4 Aluminium sulphate: Al_2(SO_4)_3 c) Carbonates (CO_3^2-) Sodium carbonate: Na_2CO_3 Magnesium carbonate: MgCO_3 Aluminium carbonate: Al_2(CO_3)_3 d) Hydrogen carbonates (HCO_3^-) Sodium hydrogen carbonate: NaHCO_3 Magnesium hydrogen carbonate: Mg(HCO_3)_2 Aluminium hydrogen carbonate: Al(HCO_3)_3 e) Nitrates (NO_3^-) Sodium nitrate: NaNO_3 Magnesium nitrate: Mg(NO_3)_2 Aluminium nitrate: Al(NO_3)_3 f) Phosphates (PO_4^3-) Sodium phosphate: Na_3PO_4 Magnesium phosphate: Mg_3(PO_4)_2 Aluminium phosphate: AlPO_4