Question

How many electrons does oxygen have in its outermost shell ?

Answer 1

Hint: The number of electrons in the outermost shell of oxygen is equal to the atomic number of the carbon. One can also say the number of electrons that an orbital in total can hold. The oxygen has 8 electrons.

Complete step by step answer:
This question is very simple. It just requires the basic knowledge of the periodic table.
From the Modern periodic, we know that Oxygen has atomic number 8.
Further, we know that the filling of electrons takes place according to Aufbau’s principle. The series of increasing energy levels according to Aufbau’s principle is as -
1s, 2s, 2p, 3s, 3p, 4s, 3d and so on.
We also know that s orbital can accommodate only two electrons, p can accommodate six electrons while the d can accommodate 10 electrons.
The Oxygen has 8 electrons in total. So, filling these eight according to Aufbau’s principle as-
$1{s^2}2{s^2}2{p^4}$
Thus, 2s orbital has 2 electrons and 2p orbital has 4 electrons. So, it will have 6 electrons in its outermost shell.

Note: It must be noted that the oxygen has atomic number 8 and the number of electrons in a neutral atom is equal to the atomic number. So, the oxygen atom has 8 electrons.
Many people get confused in such questions that the answer should be 4 because p has 4 electrons and it is the outermost one. Yes, p indeed is the outermost but p is orbital and the shell is 2nd. The second shell is the outermost shell that contains s and p orbitals partially filled.