Question

An element X has an atomic number of 15. Which of the following elements will show chemical properties similar to X?

• A. Be (4)
• B. Ne (10)
• C. O (8)
• D. N (7)

Answer 1

The correct option is D N (7)

Down a group, elements have the same number of valence electrons and identical outer shell electronic configuration. So, elements under the same group have similar chemical properties.
For the element having atomic number 15, the electronic configuration is 2,8,5.
The electronic configuration for the given elements elements is as follows:
Be (4): 2,2
Ne (10): 2,8
O (8): 2,6
N (7): 2,5
Since, out of the given elements only nitrogen has the same number of valence electrons and identical outer shell electronic configuration. Therefore, nitrogen is the element that will have similar chemical properties as X. Hence, the answer is N (7).