JEE Main · 2026 · 24 Jan 2026 · Shift 2 · p-Block Elements

Choose the INCORRECT statement

(A)Among the isotopes of carbon, $^{13} C$ is a radioactive isotope.✓ Correct
(B)Carbon exhibits negative oxidation states along with +4 and +2.
(C)Carbon cannot exceed its covalency more than four.
(D) $CO_{2}$ is the most acidic oxide among the dioxides of group of 14 elements.

Answer: (A)

Solution

The statement to be found incorrect is tested against the chemistry of carbon. Among carbon isotopes

^{12} C

and

^{13} C

are stable while

^{14} C

is the radioactive one, so calling

^{13} C

radioactive is wrong. The others are sound: carbon shows negative oxidation states (as

- 4

C H_{4}

) besides

+ 4

and

+ 2

; its covalency is limited to four by the four available valence orbitals; and

C O_{2}

is the most acidic of the group-14 dioxides. The incorrect statement is that

^{13} C

is a radioactive isotope.

JEE Main · 2026 · 24 Jan 2026 · Shift 2 · Single correct option