Write the chemical formula of the following: 1) Aluminium Sulphide 2) Magnesium tetraoxophosphate (V) 3) Mercury (II) oxide 4) Chromium (III) trioxosulphate (VI) Iron 5) Potassium tetraoxomanganate (VII)

Aluminium is in Group 13, forming an $\text{Al}^{3+}$ ion.
Sulphide is from sulfur (Group 16), forming an $\text{S}^{2-}$ ion.

To balance the $+3$ charge of $\text{Al}^{3+}$ and the $-2$ charge of $\text{S}^{2-}$, we need 2 aluminium ions and 3 sulphide ions ($2 \times +3 = +6$ and $3 \times -2 = -6$).
The chemical formula is:

2. Magnesium tetraoxophosphate (V)

Magnesium is in Group 2, forming an $\text{Mg}^{2+}$ ion.
Tetraoxophosphate (V) refers to the phosphate ion, $\text{PO}_4^{3-}$, where phosphorus has an oxidation state of +5.

To balance the $+2$ charge of $\text{Mg}^{2+}$ and the $-3$ charge of $\text{PO}_4^{3-}$, we need 3 magnesium ions and 2 phosphate ions ($3 \times +2 = +6$ and $2 \times -3 = -6$).
The chemical formula is:

3. Mercury (II) oxide

Mercury (II) indicates the $\text{Hg}^{2+}$ ion.
Oxide is from oxygen (Group 16), forming an $\text{O}^{2-}$ ion.

The $+2$ charge of $\text{Hg}^{2+}$ and the $-2$ charge of $\text{O}^{2-}$ balance each other in a 1:1 ratio.
The chemical formula is:

4. Chromium (III) trioxosulphate (VI) Iron

Chromium (III) indicates the $\text{Cr}^{3+}$ ion.
Trioxosulphate (VI) refers to the sulfate ion, $\text{SO}_4^{2-}$, where sulfur has an oxidation state of +6. (Note: "trioxo" is likely a typo for "tetraoxo" in this context, as sulfate has 4 oxygen atoms).
The word "Iron" at the end is ambiguous in this context. Assuming it is an extraneous word or a typo, we will provide the formula for Chromium (III) sulfate.

To balance the $+3$ charge of $\text{Cr}^{3+}$ and the $-2$ charge of $\text{SO}_4^{2-}$, we need 2 chromium ions and 3 sulfate ions ($2 \times +3 = +6$ and $3 \times -2 = -6$).
The chemical formula is:

5. Potassium tetraoxomanganate (VII)

Potassium is in Group 1, forming a $\text{K}^{+}$ ion.
Tetraoxomanganate (VII) refers to the permanganate ion, $\text{MnO}_4^{-}$, where manganese has an oxidation state of +7.

The $+1$ charge of $\text{K}^{+}$ and the $-1$ charge of $\text{MnO}_4^{-}$ balance each other in a 1:1 ratio.
The chemical formula is: