Give the correct order of initials `T` (true) or `F` (false) for following statements :-
(I) If an ion has `2` electrons in `K` shell, `8` electrons in `I`. Shell and `6` electrons in `M` shell, then number of `S` electrons present in that element is `6`.
(II) The maximum number of electrons in a subshell is given by `2n^(2)`
(III) If electron has magnetic quantum number `-1`, then it cannot be present in s-orbital.
(IV) Only one radial node is present in `3p` orbital.

Options

A. `"TTFF"`
B. `"FFTF"`
C. TFTT
D. `FFTF`

Explanation

To determine the correct order of initials `T` (true) or `F` (false) for the given statements, we will analyze each statement one by one.

### Step-by-Step Solution:

**Statement I:** If an ion has `2` electrons in `K` shell, `8` electrons in `L` shell, and `6` electrons in `M` shell, then the number of `S` electrons present in that element is `6`.

1. **Analysis of Electron Configuration:**
- The `K` shell can hold a maximum of `2` electrons (1s).
- The `L` shell can hold a maximum of `8` electrons (2s and 2p).
- The `M` shell can hold a maximum of `18` electrons (3s, 3p, and 3d).
- The total number of electrons in the `K`, `L`, and `M` shells is `2 + 8 + 6 = 16`.

2. **Determining the Number of `S` Electrons:**
- In the `K` shell, there is `1` s orbital (2 electrons).
- In the `L` shell, there is `1` s orbital (2 electrons).
- In the `M` shell, there is `1` s orbital (2 electrons).
- Thus, the total number of `s` electrons = `2 (from K) + 2 (from L) + 2 (from M) = 6`.

**Conclusion for Statement I:** True (T).

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**Statement II:** The maximum number of electrons in a subshell is given by `2n^2`.

1. **Understanding the Formula:**
- The formula `2n^2` gives the maximum number of electrons in a shell, not a subshell.
- For subshells, the maximum number of electrons is given by `2(2l + 1)` where `l` is the azimuthal quantum number.

**Conclusion for Statement II:** False (F).

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**Statement III:** If an electron has a magnetic quantum number `-1`, then it cannot be present in an s-orbital.

1. **Understanding Quantum Numbers:**
- The magnetic quantum number (`m_l`) can take values from `-l` to `+l`.
- For `s` orbitals, `l = 0`, thus `m_l` can only be `0`.
- If `m_l = -1`, then `l` must be `1`, which corresponds to `p` orbitals.

**Conclusion for Statement III:** True (T).

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**Statement IV:** Only one radial node is present in the `3p` orbital.

1. **Calculating Radial Nodes:**
- The number of radial nodes is given by the formula `n - l - 1`.
- For `3p`, `n = 3` and `l = 1`.
- Therefore, the number of radial nodes = `3 - 1 - 1 = 1`.

**Conclusion for Statement IV:** True (T).

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### Final Answers:
- Statement I: T
- Statement II: F
- Statement III: T
- Statement IV: T

### Summary of Answers:
- I: T
- II: F
- III: T
- IV: T

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