What are thhe atomic numbers of elements whose outermost electrons are represented by
(i) `3s^(1)` (ii) `2p^(3)` and (iii) `3d^(6)` ?

Explanation

To find the atomic numbers of elements based on their outermost electron configurations, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Electron Configuration**:
- We have three configurations to analyze:
(i) `3s^1`,
(ii) `2p^3`,
(iii) `3d^6`.

2. **Calculate the Total Number of Electrons**:
- The atomic number of an element is equal to the total number of electrons present in a neutral atom.

3. **For `3s^1`**:
- The configuration `3s^1` indicates:
- 1 electron in the 3s orbital.
- Before the 3s orbital, we fill the lower energy orbitals:
- `1s^2` (2 electrons)
- `2s^2` (2 electrons)
- `2p^6` (6 electrons)
- `3s^1` (1 electron)
- Total electrons = 2 (from 1s) + 2 (from 2s) + 6 (from 2p) + 1 (from 3s) = 11.
- Therefore, the atomic number is **11**, which corresponds to the element **Sodium (Na)**.

4. **For `2p^3`**:
- The configuration `2p^3` indicates:
- 3 electrons in the 2p orbital.
- Before the 2p orbital, we fill the lower energy orbitals:
- `1s^2` (2 electrons)
- `2s^2` (2 electrons)
- `2p^3` (3 electrons)
- Total electrons = 2 (from 1s) + 2 (from 2s) + 3 (from 2p) = 7.
- Therefore, the atomic number is **7**, which corresponds to the element **Nitrogen (N)**.

5. **For `3d^6`**:
- The configuration `3d^6` indicates:
- 6 electrons in the 3d orbital.
- Before the 3d orbital, we fill the lower energy orbitals:
- `1s^2` (2 electrons)
- `2s^2` (2 electrons)
- `2p^6` (6 electrons)
- `3s^2` (2 electrons)
- `3p^6` (6 electrons)
- `4s^2` (2 electrons)
- `3d^6` (6 electrons)
- Total electrons = 2 (from 1s) + 2 (from 2s) + 6 (from 2p) + 2 (from 3s) + 6 (from 3p) + 2 (from 4s) + 6 (from 3d) = 26.
- Therefore, the atomic number is **26**, which corresponds to the element **Iron (Fe)**.

### Final Answers:
- (i) Atomic number for `3s^1` is **11** (Sodium).
- (ii) Atomic number for `2p^3` is **7** (Nitrogen).
- (iii) Atomic number for `3d^6` is **26** (Iron).