To determine which of the statements are correct, let's analyze each statement step by step:
### Step 1: Analyze Electron Affinity of Silicon and Carbon
- **Statement**: Electron affinity of silicon is greater than that of carbon.
- **Explanation**: Carbon and silicon are in the same group of the periodic table. Generally, as you move down a group, electron affinity decreases due to the increase in atomic size, which makes it harder for the nucleus to attract additional electrons. However, in this case, silicon has a higher electron affinity than carbon because carbon's small 2p subshell leads to electron-electron repulsion when an additional electron is added. Thus, silicon's larger size allows for a more favorable addition of an electron.
- **Conclusion**: This statement is **correct**.
### Step 2: Analyze the Nature of BEO and YP2O3
- **Statement**: BEO (Beryllium Oxide) is amphoteric, and YP2O3 (Yttrium Oxide) is acidic.
- **Explanation**: Beryllium oxide (BEO) is indeed amphoteric, meaning it can react with both acids and bases. Yttrium oxide (YP2O3), being a metal oxide, is typically considered basic rather than acidic. Therefore, the statement that YP2O3 is acidic is incorrect.
- **Conclusion**: This statement is **incorrect**.
### Step 3: Compare Ionization Energies of Aluminum and Titanium
- **Statement**: The ionization energy of titanium is greater than that of aluminum.
- **Explanation**: As we move from left to right across a period, ionization energy generally increases due to the increase in nuclear charge and decrease in atomic radius. Although titanium is a transition metal (3D series) and aluminum is a post-transition metal, titanium's ionization energy is indeed higher than that of aluminum due to poor shielding from the d-electrons in titanium.
- **Conclusion**: This statement is **correct**.
### Step 4: Compare Ionization Energies of Copper Group and Zinc Group
- **Statement**: The ionization energy of the copper group is less than that of the respective elements of the zinc group.
- **Explanation**: The copper group (Group 11) typically has lower ionization energies compared to the zinc group (Group 12) due to the presence of filled d-orbitals in zinc, which leads to greater stability and higher ionization energy. Thus, this statement holds true.
- **Conclusion**: This statement is **correct**.
### Final Conclusion
Based on the analysis:
- Statement 1: Correct
- Statement 2: Incorrect
- Statement 3: Correct
- Statement 4: Correct
Thus, the correct statements are 1, 3, and 4.
### Summary of Correct Statements
- The correct statements are: 1, 3, and 4.
