Which of the following enzymes is present in tears and kills bacteria? MCQ with Answer and Explanation

Explanation:
Down a group, number of shells increases, atomic radius increases, and inner electrons shield the outermost electron from the nucleus. The effective nuclear charge experienced by valence electron decreases, making it easier to remove. Thus ionization energy decreases. For example, IE of Cs

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.

Explanation:
Cooking of food involves chemical reactions (e.g., denaturation of proteins, caramelization of sugars) that form new substances, making it a chemical change. Dissolving sugar in water is a physical change because no new substance is formed (sugar can be recovered by evaporation). Breaking glass is a physical change (change in size/shape). Melting wax is a physical change (change of state).