Chemical Bonding and Atomic Structure MCQs for NEET — Chemistry Questions with Answers

The stability of diatomic molecules can be compared using Molecular Orbital Theory. According to this theory, the bond order of $O_2$ is 2, which makes it more stable compared to $O_2^-$ (bond order 1.5), $Ne_2^+$ (bond order 0.5, unstable), and $F_2$ (bond order 1). Therefore, $O_2$ is the most stable species among the given options.

Metallic bonds are characterized by a 'sea of electrons' that are delocalized over a lattice of metal cations. The metallic bond is non-directional, meaning that the strength of the bond is the same in all directions, unlike covalent bonds which are directional. Therefore, the statement that 'Directional property is shown by metal' is incorrect.

Number of H - bond form by unpaired electrons of liquid NH3 , H2O and HF respectively are  1, 2, 1 

The boiling points of compounds in groups 14, 15, 16, and 17 generally increase with increasing molecular weight and size. However, due to hydrogen bonding, there are exceptions. For example, $H_2O$ has a higher boiling point than $H_2S$, $HF$ has a higher boiling point than $HCl$, and $NH_3$ has a higher boiling point than $PH_3$. But $CH_4$ has a lower boiling point than $SiH_4$. So, the correct pair that is not in order is $CH_4 extgreater SiH_4$.

Ionic bonds are formed between metals and non-metals due to the transfer of electrons. Among the given options, $MgCl_2$ (magnesium chloride) is an ionic compound because it is formed from magnesium (a metal) and chlorine (a non-metal). The other options are covalent compounds.

The bond energy of a hydrogen bond is typically around 40 kJ/mol. This value indicates the amount of energy required to break the hydrogen bond and is significantly stronger than van der Waals forces but weaker than covalent bonds. Hence, option o2 is correct.

Intermolecular hydrogen bonding is possible in molecules where hydrogen is directly bonded to highly electronegative atoms such as nitrogen, oxygen, or fluorine. In the given options, $NH_3$ (ammonia) has hydrogen atoms bonded to nitrogen, making intermolecular hydrogen bonding possible. Therefore, option o4 is correct.