Question

Drag electrons back and forth until the molecule of oxygen (O2) is stable. Click Check to confirm your molecule is stable. How many pairs of shared electrons are there in a stable molecule of oxygen?

Answer 1

2 pairs (4 electrons)

Step-by-step explanation:

In a molecule of oxygen there are 2 oxygen atoms. There are 6 electrons in the outer shells of oxygen atoms. When 2 oxygen atoms form a covalent bond they share their electrons. In a diagram this would be represented by the overlap of the two circles representing the outer shells of both oxygen atoms. If each oxygen atom 'puts forward' 2 electrons into the centre, then 4 will be shared overall for each atom, making both atoms have full outer shells of 8 electrons each. 4 electrons make 2 pairs, hence the answer.