In a period of the periodic table as we move from left to right usually

Options

A. atomic radlus decreases
B. lonisation potential increases
C. electron affinity decreases
D. electronegativity increases
Among the above statements, which one is false?

Explanation

To solve the question, we need to analyze the statements regarding the trends in the periodic table as we move from left to right in a period. Let's break down each option step by step:

### Step 1: Analyze Atomic Radius
- **Statement A**: Atomic radius decreases.
- As we move from left to right in a period, the atomic radius generally decreases. This is because electrons are added to the same principal energy level while the number of protons in the nucleus increases. The increased positive charge pulls the electrons closer to the nucleus, resulting in a smaller atomic radius.

**Hint**: Remember that increased nuclear charge pulls electrons closer, reducing atomic size.

### Step 2: Analyze Ionization Potential
- **Statement B**: Ionization potential increases.
- Ionization potential (or ionization energy) is the energy required to remove an electron from an atom. As we move from left to right across a period, the ionization potential generally increases. This is due to the decrease in atomic radius and the increase in nuclear charge, making it harder to remove an electron.

**Hint**: Higher nuclear charge and smaller size lead to higher ionization energy.

### Step 3: Analyze Electron Affinity
- **Statement C**: Electron affinity decreases.
- Electron affinity is the energy change when an atom gains an electron. Typically, as we move from left to right, electron affinity increases. This is due to the increased nuclear charge, which attracts additional electrons more strongly.

**Hint**: More protons in the nucleus mean stronger attraction for added electrons.

### Step 4: Analyze Electronegativity
- **Statement D**: Electronegativity increases.
- Electronegativity is the tendency of an atom to attract electrons in a bond. As we move from left to right across a period, electronegativity generally increases for similar reasons: increased nuclear charge and decreased atomic radius.

**Hint**: Higher electronegativity means stronger attraction for shared electrons.

### Conclusion
Now that we have analyzed each statement:
- **Statement A**: True (Atomic radius decreases)
- **Statement B**: True (Ionization potential increases)
- **Statement C**: False (Electron affinity increases, not decreases)
- **Statement D**: True (Electronegativity increases)

The false statement among the options is **Statement C**: Electron affinity decreases.

### Final Answer
The false statement is **C: Electron affinity decreases**.