The mass number of an atom is the sum of: MCQ with Answer and Explanation

Explanation:
Gamma rays are high-frequency electromagnetic waves emitted from the nucleus. They have very high penetration power and are used in cancer therapy.

Explanation:
Fermentation of sugars (glucose, fructose) by yeast enzymes produces ethanol and carbon dioxide: C₆H₁₂O₆ → 2C₂H₅OH + 2CO₂. Starch is first hydrolysed to glucose. Proteins and fats are not directly fermented to ethanol.

Explanation:
All matter is composed of tiny particles (atoms, molecules, or ions). This is a fundamental concept. Matter may not always be visible (e.g., air). It can change states (solid, liquid, gas). Gases have mass; for example, a filled gas cylinder weighs more than an empty one. The particulate nature of matter explains diffusion, Brownian motion, etc.