Understanding Polyatomic Ions:
– Definition: Polyatomic ions are groups of atoms bonded together, carrying an electric charge. They act as a single charged unit in chemical reactions.

– Composition: These ions are made of two or more different types of atoms covalently bonded together.

– Charge: They have an overall electrical charge due to the gain or loss of electrons. This charge results from the combined effect of the atoms within the ion.

Importance and Behavior:
– Polyatomic ions play crucial roles in chemical compounds and reactions.
– They bond with other ions or atoms, forming molecules or ionic compounds with distinctive properties.
– Due to their unique structures and charges, polyatomic ions exhibit behavior distinct from individual atoms.

Conclusion:
Polyatomic ions are combinations of atoms that act as single charged units, influencing the properties and behavior of various chemical compounds. Their ability to bond with other elements forms the basis for many essential chemical reactions in nature and in the laboratory.

(a) Quick lime: The compound for quick lime is Calcium oxide (CaO). The elements present in quick lime are:
– Calcium (Ca)
– Oxygen (O)

(b) Hydrogen bromide: The compound for hydrogen bromide is Hydrobromic acid (HBr). The elements present in hydrogen bromide are:
– Hydrogen (H)
– Bromine (Br)

(c) Baking powder: Baking powder is a mixture that often contains compounds like sodium bicarbonate (NaHCO3) and an acid, such as cream of tartar (potassium hydrogen tartrate -KHC4H4O6). The elements present in baking powder can include:
– Sodium (Na)
– Hydrogen (H)
– Carbon (C)
– Oxygen (O)
– Potassium (K)
– Tartaric acid: Carbon (C), Hydrogen (H), Oxygen (O)

(d) Potassium sulphate: The compound for potassium sulphate is (K2SO4). The elements present in potassium sulphate are:
– Potassium (K)
– Sulfur (S)
– Oxygen (O)