Question

Match List I with List II

List I Element	List II Number of Neutron
(A). \(_{12}^{24}Mg\)	(I). \(5\)
(B). \(_{13}^{27}Al\)	(II). \(12\)
(C). \(_4^9Be\)	(III). \(6\)
(D). \(_6^{12}C\)	(IV). \(14\)

Choose the correct answer from the options given below:

• (A) - (I), (B) - (II), (C) - (III), (D) - (IV)
• (A) - (II), (B) - (IV), (C) - (I), (D) - (III)
• (A) - (I), (B) - (II), (C) - (IV), (D) - (III)
• (A) - (III), (B) - (IV), (C) - (I), (D) - (II)

Hint:

Neutrons = mass number minus atomic number.

Answer 1

The Correct Option is B

Step 1: State the rule
Number of neutrons \(=A-Z\), where \(A\) is the mass number (top) and \(Z\) is the atomic number (bottom).

Step 2: Calculate each
(A) Mg: \(24-12=12\), which is (II).
(B) Al: \(27-13=14\), which is (IV).
(C) Be: \(9-4=5\), which is (I).
(D) C: \(12-6=6\), which is (III).

Step 3: Match with options
The pairing is A-II, B-IV, C-I, D-III, which is option (B). The other options pair at least one element with a wrong neutron count.

Final Answer:
The matching is A-II, B-IV, C-I, D-III, option (B). \[ \boxed{\text{(B)}} \]