The purity of water can be checked by measuring its: MCQ with Answer and Explanation

Explanation:
Isotopes are atoms of the same element with the same atomic number (protons) but different mass numbers due to varying number of neutrons. For example, protium (¹H) has 0 neutrons, deuterium (²H) has 1, tritium (³H) has 2. Chemical properties are nearly identical because electronic configuration is the same, but physical properties (mass, density) differ.

Explanation:
Bleaching powder is chemically calcium oxychloride, with the formula CaOCl₂. It is produced by the action of chlorine gas on dry slaked lime (Ca(OH)₂). Option A is slaked lime, C is plaster of Paris, and D is washing soda. It is used for disinfecting water and bleaching textiles.

Explanation:
In H₂, two hydrogen atoms share their electrons equally because they have the same electronegativity. Thus, a non-polar covalent bond is formed. Ionic bonds form between metals and non-metals. Polar covalent bonds involve unequal sharing (e.g., HCl). Coordinate bonds involve one atom donating both electrons (e.g., NH₄⁺).