Which of the following statement are not correct :-

Options

A. The electron affinity of 'Si' is greater than of C
B. BeO is amphoteric while `B_(2)O_(3)` is acidic
C. The ionisation energy of 'Ti' is less than that of Al
D. The ionisation energy of elements of 'Cu' group is less than that of the respective elements Zn-group

Answer

To determine which statements are not correct, we will analyze each statement one by one.

### Step 1: Analyze Statement 1
**Statement 1:** The electron affinity of silicon is greater than that of carbon.

- **Analysis:** Carbon (C) and silicon (Si) are both in Group 14 of the periodic table. As we move down the group from carbon to silicon, the atomic size increases. Larger atomic size generally means that the added electron is further from the nucleus, which can lead to a decrease in electron affinity. Therefore, the electron affinity of silicon is actually less than that of carbon.

**Conclusion:** Statement 1 is **not correct**.

### Step 2: Analyze Statement 2
**Statement 2:** BeO is amphoteric.

- **Analysis:** Beryllium oxide (BeO) is indeed amphoteric, meaning it can react with both acids and bases. This is a characteristic behavior of beryllium compounds due to the small size and high charge density of the beryllium ion.

**Conclusion:** Statement 2 is **correct**.

### Step 3: Analyze Statement 3
**Statement 3:** The ionization energy of titanium is less than that of aluminum.

- **Analysis:** The electronic configuration of aluminum (Al) is [Ne] 3s² 3p¹, while that of titanium (Ti) is [Ar] 4s² 3d². The presence of d-orbitals in titanium leads to a shielding effect, which generally results in lower ionization energy. However, in this case, the ionization energy of titanium is actually greater than that of aluminum due to the effective nuclear charge and the electron configuration.

**Conclusion:** Statement 3 is **not correct**.

### Step 4: Analyze Statement 4
**Statement 4:** The ionization energy of copper is less than that of zinc.

- **Analysis:** Copper (Cu) and zinc (Zn) are in the same period of the periodic table. As we move from left to right across a period, the ionization energy generally increases. Since zinc is to the right of copper, it has a higher ionization energy than copper.

**Conclusion:** Statement 4 is **correct**.

### Final Conclusion
The statements that are **not correct** are:
- Statement 1: The electron affinity of silicon is greater than that of carbon.
- Statement 3: The ionization energy of titanium is less than that of aluminum.