Select the incorrect statement(s)/order (s):

Options

A. d-orbital can accommodate 10 electrons
B. `underset(2s^(2)2p^(6)3s^(1))(Na) overset(I.E_(1)) underset(2s^(2)2p^(6))(Na^(+)) overset(I.E_(2)) to underset(2s^(2)2p^(5))(Na^(2+)) overset(I.E_(3)) to underset(2s^(2)2p^(4)) (Na^(3+))`, order of successive I.E. is `I.E_(1) lt I.E_(2) lt I.E_(3)`
C. Number of unpiared electrons in `Co^(2+)` cationgt Number of unpaired electrons in `Co^(3+)` cation
D. First ionisation energy of Pt is greater than that of Pd

Answer

To solve the question of selecting the incorrect statement(s) or order(s), we will analyze each statement provided in the video transcript step by step.

### Step 1: Analyze the first statement
**Statement:** "d orbital can accommodate 10 electrons."
- **Explanation:** The d orbital consists of five subshells (dxy, dyz, dxz, dx2-y2, dz2), and each subshell can hold a maximum of 2 electrons. Therefore, the total capacity of the d orbital is 5 subshells × 2 electrons = 10 electrons.
- **Conclusion:** This statement is **correct**.

### Step 2: Analyze the second statement
**Statement:** "On sodium, when the first ionization enthalpy is applied, it changes into 3s to 3p6. When second ionization energy is applied, then it changes into 2s to 2p5 and again changes to 2s to 2p4."
- **Explanation:** The first ionization of sodium (Na) removes one electron from the 3s orbital, resulting in Na+ with the configuration of 3s^0. The second ionization energy does not apply to sodium because it only has one electron in the outer shell. The statement seems to confuse the ionization process. The correct sequence for sodium would be Na → Na+ (after first ionization) and Na+ does not go to 3p6.
- **Conclusion:** This statement is **incorrect**.

### Step 3: Analyze the third statement
**Statement:** "The number of unpaired electrons in Co2+ is greater than that of Co3+."
- **Explanation:** The electronic configuration of cobalt (Co) is [Ar] 3d^7 4s^2. For Co2+, the configuration is [Ar] 3d^7, which has 3 unpaired electrons. For Co3+, the configuration is [Ar] 3d^6, which has 4 unpaired electrons. Therefore, Co3+ has more unpaired electrons than Co2+.
- **Conclusion:** This statement is **incorrect**.

### Step 4: Analyze the fourth statement
**Statement:** "The first ionization energy of platinum is greater than that of palladium."
- **Explanation:** As we move down the group in the periodic table, the ionization energy generally decreases due to increased atomic size and shielding effect. However, platinum (Pt) is below palladium (Pd) in the periodic table, and typically, ionization energy decreases down a group. Thus, this statement is **incorrect** because the first ionization energy of platinum is actually less than that of palladium.
- **Conclusion:** This statement is **incorrect**.

### Final Conclusion
The incorrect statements are:
1. The second statement regarding sodium's ionization process.
2. The third statement regarding the number of unpaired electrons in Co2+ and Co3+.
3. The fourth statement regarding the ionization energies of platinum and palladium.

### Summary of Incorrect Statements
- The second statement about sodium's ionization process is incorrect.
- The third statement about unpaired electrons in Co2+ and Co3+ is incorrect.
- The fourth statement about ionization energies of platinum and palladium is incorrect.