Certainly! Let's determine the chemical formulas for the compounds formed by each pair of elements and ions:
### (a) \( Ca \) and \( S \)
Calcium (Ca) typically forms a +2 charge, and Sulfur (S) typically forms a -2 charge. When these ions combine, the charges will balance each other out, forming a neutral compound. Thus, the compound formed is:
[tex]\[ \text{CaS} \][/tex]
### (b) \( NH_4 \) and \( SO_4 \)
Ammonium (NH\(_4\)) has a +1 charge, and Sulfate (SO\(_4\)) has a -2 charge. To balance the charges, we need two ammonium ions for every sulfate ion. This means two ammonium (\(NH_4^+\)) ions will combine with one sulfate (\(SO_4^{2-}\)) ion:
[tex]\[ \text{(NH}_4\text{)}_2\text{SO}_4 \][/tex]
### (c) \( Al \) and \( Br \)
Aluminum (Al) typically forms a +3 charge, and Bromine (Br) typically forms a -1 charge. To balance the charges, we need three bromine ions for every aluminum ion. Thus, one aluminum (\(Al^{3+}\)) ion will combine with three bromine (\(Br^-\)) ions:
[tex]\[ \text{AlBr}_3 \][/tex]
### (d) \( Na \) and \( HPO_4 \)
Sodium (Na) typically forms a +1 charge, and Hydrogen Phosphate (HPO\(_4\)) has a -2 charge. To balance the charges, we need two sodium ions for every hydrogen phosphate ion. Therefore, two sodium (\(Na^+\)) ions will combine with one hydrogen phosphate (\(HPO_4^{2-}\)) ion:
[tex]\[ \text{Na}_2\text{HPO}_4 \][/tex]
Thus, the formulas for the compounds formed are:
- (a) \( \text{CaS} \)
- (b) \( \text{(NH}_4\text{)}_2\text{SO}_4 \)
- (c) \( \text{AlBr}_3 \)
- (d) [tex]\( \text{Na}_2\text{HPO}_4 \)[/tex]
