When two atomic orbitals combine,they form:

Which of the following statements is incorrect when $C_2$ changes to $C_2^{2-}$?

Which of the following species contain unpaired electrons: $KO_2, AlO_2^-, BaO_2$,and $NO_2^+$?

Which of the following molecule$(s)$ show$(s)$ paramagnetic behavior?
$(A) O_2$ $(B) N_2$ $(C) F_2$ $(D) S_2$ $(E) Cl_2$
Choose the correct answer from the options given below:

The bond lengths of diatomic molecules of elements $X$,$Y$ and $Z$ respectively are $143 \text{ pm}$,$110 \text{ pm}$ and $121 \text{ pm}$. The atomic numbers of $X$,$Y$ and $Z$ respectively are:

Which set consists of paramagnetic molecules or ions?