Ionic compounds have high melting points because: MCQ with Answer and Explanation

Explanation:
Half-life (T₁/₂) is the time taken for the number of radioactive nuclei (or activity) to decrease to half of its original value. It's a constant characteristic of each radioisotope. For example, C-14 half-life is 5730 years.

Explanation:
In this reaction, chlorine (oxidation state 0) reacts with hot, concentrated NaOH. It forms NaCl where Cl is -1 (reduction) and NaClO3 where Cl is +5 (oxidation). Since the same element, chlorine, is both oxidized and reduced, it undergoes a disproportionation reaction.

Explanation:
Electrolysis of water decomposes it into hydrogen and oxygen, not purification. Boiling kills microbes, filtration removes particulate matter, chlorination disinfects. Other methods: UV treatment, ozonation, reverse osmosis, distillation. Electrolysis is a chemical decomposition technique.