To determine which of the statements is true, we need to analyze each option provided in the question.
### Step-by-Step Solution:
1. **Understanding Ionization Energy**:
- Ionization energy is defined as the energy required to remove an electron from an atom.
- In Group 14 (which includes Carbon, Silicon, Germanium, Tin, and Lead), as we move down the group, the atomic size increases. This increase in size leads to a decrease in ionization energy because the outermost electrons are further from the nucleus and experience less nuclear attraction.
2. **Evaluating Statement 1**:
- The statement claims that "the lowest ionization energy in group 14 is possessed by Tin (Sn)".
- As we have established, Tin is indeed the element with the lowest ionization energy in Group 14 due to its position in the group. Therefore, this statement is **true**.
3. **Understanding Electron Affinity**:
- Electron affinity is the energy change when an electron is added to a neutral atom to form a negative ion.
- In Group 16 (which includes Oxygen, Sulfur, Selenium, etc.), the trend shows that as we move down the group, the electron affinity generally decreases.
4. **Evaluating Statement 2**:
- The statement claims that "the lowest electron affinity in group 16 is that of Oxygen".
- This is incorrect. Oxygen has a high electron affinity because it is highly electronegative. Therefore, this statement is **false**.
5. **Understanding Electron Gain Enthalpy**:
- Electron gain enthalpy is a measure of the energy change when an electron is added to an atom.
- In Group 17 (the Halogens, which includes Fluorine, Chlorine, Bromine, and Iodine), the trend is that electron gain enthalpy generally decreases as we move down the group.
6. **Evaluating Statement 3**:
- The statement claims that "the highest value of electron gain enthalpy is possessed by Chlorine".
- Chlorine does have a high electron gain enthalpy, but it is not the highest; Fluorine has the highest due to its smaller atomic size and greater electronegativity. Therefore, this statement is **false**.
7. **Evaluating Statement 4**:
- The statement claims that "all of these are correct".
- Since we have established that Statements 2 and 3 are false, this statement is also **false**.
### Conclusion:
The only true statement is Statement 1: "The lowest ionization energy in group 14 is possessed by Tin (Sn)".
