Which of the following is a metal? MCQ with Answer and Explanation

Explanation:
Red litmus turning blue indicates that the solution is basic. Basic solutions have a pH greater than 7. Among the options, 10 is the only value greater than 7. pH 1 and 4 are acidic (turn blue litmus red), and 7 is neutral (no change in litmus color).

Explanation:
Detergents emulsify grease by forming micelles around oil droplets, removing them from fabric. Soap does same but less effective in hard water.

Explanation:
Soap is made by saponification of triglycerides (fats/oils) which are esters of glycerol and long-chain fatty acids (e.g., stearic, palmitic, oleic). The sodium salt gives hard soap, potassium gives soft soap. The long hydrocarbon chain (hydrophobic) and carboxylate head (hydrophilic) provide cleaning action via micelle formation. Synthetic detergents are usually sodium salts of sulfonic acids or sulfate esters.