All the elements, on the basis of long form of periodic table, can be divided into four blocks, s,p, d and f. the ionization energies, electron affinities, electronegativities, atomic and ionic radii and other physical properties usually shown a regular pattern of change within a group or along period with some irregularities.
Q. On moving from Li to F in the second period, there would be a decrease in :

Options

A. non-metallic property
B. atomic radius
C. ionization potential
D. electronegativity

Answer

To solve the question regarding the change in properties when moving from lithium (Li) to fluorine (F) in the second period of the periodic table, we will analyze each property mentioned in the question step by step.

### Step-by-Step Solution:

1. **Understanding the Elements**:
- Lithium (Li) is an alkali metal, while fluorine (F) is a halogen and a non-metal.
- As we move from left to right across a period, the nature of the elements changes from metallic to non-metallic.

**Hint**: Identify the position of the elements in the periodic table to understand their properties.

2. **Analyzing Metallic and Non-metallic Character**:
- As we move from Li to F, the metallic character decreases and the non-metallic character increases.
- Therefore, non-metallic properties do not decrease; they actually increase.

**Hint**: Remember that metallic character decreases and non-metallic character increases across a period.

3. **Examining Atomic Radius**:
- The atomic radius generally decreases as we move from left to right across a period due to an increase in the effective nuclear charge (Z effective).
- As Z effective increases, the electrons are pulled closer to the nucleus, resulting in a smaller atomic radius.

**Hint**: Consider how the effective nuclear charge affects the size of the atom.

4. **Ionization Energy**:
- Ionization energy is the energy required to remove an electron from an atom.
- As we move from Li to F, the ionization energy increases due to the increase in Z effective.

**Hint**: Ionization energy typically increases across a period due to increased nuclear charge.

5. **Electronegativity**:
- Electronegativity is the tendency of an atom to attract electrons in a bond.
- Similar to ionization energy, electronegativity increases as we move from Li to F due to the increase in Z effective.

**Hint**: Electronegativity trends follow the same pattern as ionization energy across a period.

6. **Conclusion**:
- The only property that decreases when moving from Li to F is the atomic radius.
- Therefore, the correct answer to the question is that there would be a decrease in **atomic radius**.

### Final Answer:
The property that decreases when moving from Li to F in the second period is the **atomic radius**.