Assertion (A): Radioactive decay is a nuclear process. Reason (R): It involves changes in the nucleus of an atom. MCQ with Answer and Explanation

Explanation:
In BF₃, boron has 3 valence electrons and forms 3 covalent bonds with fluorine, resulting in only 6 electrons in its valence shell. It does not complete its octet, making it an electron-deficient molecule and a strong Lewis acid. NH₃, H₂O, and CH₄ all have complete octets.

Explanation:
Fermentation is an anaerobic biological process in which enzymes (zymase) convert glucose to ethanol and CO₂: C₆H₁₂O₆ → 2C₂H₅OH + 2CO₂. Oxidation would require oxygen. Esterification forms esters, saponification makes soap. Fermentation is used in brewing, winemaking, and baking (where CO₂ makes bread rise). The temperature is kept around 30-35°C.

Explanation:
Neutralization is the reaction of an acid with a base to produce salt and water. However, the resulting solution is not always neutral (pH 7) because the salt may undergo hydrolysis. If the acid is strong and base weak (e.g., HCl + NH₄OH), the salt (NH₄Cl) is acidic, pH < 7. If acid is weak and base strong (CH₃COOH + NaOH), salt is basic, pH > 7. Only strong acid-strong base gives pH 7.