Which element is in Group 2, Period 4 of the periodic table? MCQ with Answer and Explanation

Explanation:
Enzymes are proteins with complex three-dimensional structures maintained by hydrogen bonds, ionic bonds, and hydrophobic interactions. Extremes of pH or high temperature disrupt these bonds, causing denaturation (loss of structure and function). Each enzyme has an optimum pH and temperature. For example, pepsin works in acidic stomach, trypsin in alkaline intestine.

Explanation:
Rusting is a chemical change because iron reacts with atmospheric oxygen and moisture to form hydrated iron(III) oxide. This new compound possesses entirely different chemical properties from the original iron. The process involves the formation of new chemical bonds and cannot be easily reversed by simple physical methods.

Explanation:
A separating funnel allows immiscible liquids to form layers; the denser liquid is drained from the bottom. Fractionating column is for miscible liquids with close boiling points, condenser for distillation, centrifuge for separating fine solids or liquids of different densities by spinning.