The electronic configurations of some elements are given below:
(i) `1s ^(2) 2s ^(2) 2p ^(6) 3s ^(1)`
(ii) `1s ^(2) 2s ^(2) 2p ^(6) 3s ^(2) 3p ^(6) 4s ^(2) 3s ^(1)`
(iii) `1s ^(2) 2s ^(2) 2p ^(3)`
(iv) ` 1s ^(2) 2s ^(2) 2p ^(6) 3s ^(2) 3p ^(6) 4s ^(2)`
(v) `1s ^(2) 2s ^(2) 2p ^(6) 3s^(2) 3p ^(5)`
(vi ) `1s ^(2) 2s ^(2) 2p^(6) 3s ^(2) 3p ^(3)`
(vii) `1s^(2) 2s ^(2) 2p^(6)`
(viii) `1s ^(2) 2s ^(2) 2p ^(6) 3s ^(2) 3p ^(4)`
Name the elements. Out of these which
1. is an alkaline earth metal
2. has lowest chemical reactivity
3. belong to group 15 of the periodic table
4. is a transition element
5. is halogen
6. belong to p-block
7. belong to second period.

Explanation

To solve the question, we need to identify the elements corresponding to the given electronic configurations and then answer the specific queries regarding their properties.

### Step-by-Step Solution:

1. **Identify the Elements from Electronic Configurations:**
- (i) `1s^2 2s^2 2p^6 3s^1`: Total electrons = 11. This corresponds to Sodium (Na).
- (ii) `1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^1`: Total electrons = 21. This corresponds to Scandium (Sc).
- (iii) `1s^2 2s^2 2p^3`: Total electrons = 7. This corresponds to Nitrogen (N).
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