Choose the INCORRECT statement
Q. Choose the INCORRECT statement

(A) Carbon exhibits negative oxidation states along with +4 and +2.

(B) Carbon cannot exceed its covalency more than four.

(C) Among the isotopes of carbon, ¹³C is a radioactive isotope.

(D) CO₂ is the most acidic oxide among the dioxides of group of 14 elements.

Correct Answer: Among the isotopes of carbon, ¹³C is a radioactive isotope.

Explanation

Option (A): True. Carbon shows oxidation states like −4 (CH₄), +2 (CO) and +4 (CO₂).

Option (B): True. Carbon cannot expand its octet due to absence of vacant d-orbitals, so its covalency cannot exceed four.

Option (C): False. ¹³C is a stable isotope of carbon. The radioactive isotope of carbon is ¹⁴C.

Option (D): True. Acidity of group 14 dioxides decreases down the group, hence CO₂ is the most acidic.

Therefore, the incorrect statement is option (C).

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Updated for JEE Main 2026: This PYQ is important for JEE Mains, JEE Advanced and other competitive exams. Practice more questions from this chapter.

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