Which of the following is an example of a broad-spectrum antibiotic? MCQ with Answer and Explanation

Explanation:
Atomic number (Z) = Mass number (A) – Number of neutrons (N) = 39 – 20 = 19. This is potassium (K). Number of protons equals atomic number. In a neutral atom, electrons also equal Z.

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.

Explanation:
Amphoteric oxides react with both acids and bases to form salts and water. Aluminum oxide (Al₂O₃) and Zinc oxide (ZnO) are classic examples. Na₂O and MgO are basic oxides that react only with acids, while SO₂ is an acidic oxide that reacts only with bases.