Question

What is the electron configuration of an element with atomic number 15? A. 1s2 2s2 2p6 B. 1s2 2s2 2p6 3s2 3p5 C. 1s2 2s2 2p6 3s2 3p3 D. 1s2 2s2 2p6 3s2 E. 1s2 2s2 2p6 3p3 3s2 3p1

Answer 1

Answer: The correct answer is option C.

Explanation:

Electronic configuration of an element is defined as the distribution of electrons in sub-shells of an element.

We are given an element of atomic number 15.

We know that,

Atomic number = Number of electrons = Number of protons

Number of electrons = 15

For filling of electrons, the orbitals of lower energy will be filled first. The filling of orbitals follow the pattern: 1s, 2s, 2p, 3s, 3p, 4s, 3d and so on..

So, the electronic configuration of element having atomic number 15 is: $1s^22s^22p^63s^23p^3$

Hence, the correct answer is Option C.

Answer 2

B 
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