Which of the following is true ?

Options

A. (1) Dipositive zinc exhibits paramagnetism due to loss of two electrons from a `3d` orbital of neutral atom.
B. (2) In `beta` emission from a nucleus , the atomic number of the daughter element decreases by `1`
C. (3) The emission of one `alpha` particle from a radioactive atom results in the decrease of atomic number by `2` and mass number by `4`
D. (4) The successive atom result in the decrease of atomic number by `11`, by loss of an alpha particle.

Explanation

To solve the question "Which of the following is true?", we will evaluate each statement provided in the video transcript step by step.

### Step 1: Evaluate the first statement
**Statement:** "Dipositive zinc exhibits paramagnetism due to loss of two electrons from a 3D orbital of neutral atom."

- **Analysis:**
- The atomic number of zinc (Zn) is 30, and its electronic configuration is \( \text{[Ar]} 4s^2 3d^{10} \).
- When zinc loses two electrons to form a dipositive ion (\( \text{Zn}^{2+} \)), the electrons are removed from the 4s orbital first, not from the 3d orbital.
- The electronic configuration of \( \text{Zn}^{2+} \) becomes \( \text{[Ar]} 3d^{10} \).
- Since all electrons in the 3d subshell are paired, \( \text{Zn}^{2+} \) is actually diamagnetic, not paramagnetic.

**Conclusion:** The first statement is **false**.

### Step 2: Evaluate the second statement
**Statement:** "In a beta emission from a nucleus, the atomic number of the daughter element decreases by one."

- **Analysis:**
- In beta decay, a beta particle (electron) is emitted from the nucleus.
- The emission of a beta particle increases the atomic number by 1 because a neutron is converted into a proton.
- Therefore, the atomic number of the daughter element actually increases by 1, not decreases.

**Conclusion:** The second statement is **false**.

### Step 3: Evaluate the third statement
**Statement:** "The emission of one alpha particle from a radioactive atom results in the decrease of atomic number by two and mass number by two."

- **Analysis:**
- An alpha particle consists of 2 protons and 2 neutrons (essentially a helium nucleus).
- When an alpha particle is emitted, the atomic number decreases by 2 (because 2 protons are lost) and the mass number decreases by 4 (because 2 protons and 2 neutrons are lost).
- Thus, the statement correctly states that the atomic number decreases by 2, but incorrectly states that the mass number decreases by 2 instead of 4.

**Conclusion:** The third statement is **partially true**, but the mass number decrease is incorrectly stated.

### Step 4: Evaluate the fourth statement
**Statement:** "The successive atom results in the decrease of atomic number by 11 by loss of an alpha particle."

- **Analysis:**
- As established, the emission of an alpha particle decreases the atomic number by 2, not by 11.

**Conclusion:** The fourth statement is **false**.

### Final Conclusion
The only statement that is partially true is the third statement regarding alpha decay, but it contains an error regarding the mass number. Therefore, if we strictly adhere to the question of which statement is true, we conclude that none of the statements are completely correct. However, if we consider the context, the third statement is the closest to being true regarding the decrease in atomic number.

### Correct Answer
The correct answer to the question "Which of the following is true?" is **none of the statements are entirely true**, but the third statement is the most accurate regarding the atomic number decrease.

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