How many unpaired electrons are there in an atom of an element with the following electronic configuration? 1s²2s²2p⁶

To find unpaired electrons, we need to understand how electrons fill orbitals. Each orbital can hold a maximum of 2 electrons, and when both electrons are present in an orbital, they are said to be “paired” (they spin in opposite directions).

Let us look at the electronic configuration 1s²2s²2p⁶:

The 1s orbital has 2 electrons → both paired (0 unpaired).
The 2s orbital has 2 electrons → both paired (0 unpaired).
The 2p subshell has 3 orbitals (2pₓ, 2pᵧ, 2p_z), and it holds 6 electrons. That means each of the 3 orbitals has exactly 2 electrons → all paired (0 unpaired).

Total unpaired electrons = 0 + 0 + 0 = 0

This configuration (1s²2s²2p⁶) has 10 electrons total and represents neon (Ne), a noble gas. Noble gases have completely filled electron shells, which is why all their electrons are paired and they are very stable and unreactive.

If the 2p subshell had fewer than 6 electrons, there would be unpaired electrons. For example, 2p⁴ (like oxygen) has 2 unpaired electrons, and 2p³ (like nitrogen) has 3 unpaired electrons. But 2p⁶ is completely full, so there are zero unpaired electrons.