In the following questions, a statement I is given and a corresponding statement II follows it. Mark the correct answer as:

Statement I: Smaller is the size of an atom greater is the electronegativity.

Statement II: Electronegativity refers to the tendency of atom to share electrons.

If statement I is true but statement II is false.

The  correct answer is option 3. If statement I is true but statement II is false.

Let us break down the statements and the reasoning behind the correct answer in detail:

Statement I: Smaller is the size of an atom, greater is the electronegativity.

Electronegativity is the tendency of an atom to attract electrons in a chemical bond. As the size of an atom decreases, the distance between the nucleus and the valence electrons decreases. This results in a stronger effective nuclear charge (the net positive charge experienced by valence electrons). Smaller atoms (those with fewer electron shells) have their valence electrons closer to the nucleus. This stronger attraction to the nucleus means that these atoms are more effective at attracting electrons in a bond. Example: Fluorine (F) is a small atom with high electronegativity, whereas cesium (Cs) is a large atom with low electronegativity.

Therefore, Statement I is true.

Statement II: Electronegativity refers to the tendency of an atom to share electrons.

Electronegativity is actually defined as the ability of an atom to attract electrons toward itself in a chemical bond, not just to share them. While atoms in a covalent bond do share electrons, electronegativity specifically measures how strongly an atom can attract the shared electrons towards itself. If an atom has high electronegativity, it pulls the shared electrons closer, creating a polar covalent bond if paired with a less electronegative atom. Saying that electronegativity is just about the tendency to share electrons is misleading because it doesn't capture the aspect of attracting electrons.

Therefore, Statement II is false.

Statement I is true: Smaller atomic size correlates with higher electronegativity.

Statement II is false: Electronegativity refers to the attraction for electrons, not merely sharing them.

Thus, the correct answer is 3. If statement I is true but statement II is false.

This accurately reflects that the first statement about the relationship between atomic size and electronegativity is correct, while the second statement provides an incorrect definition of electronegativity.