The number of electron pairs shared by the two carbon atoms which are bonded by a double bond are.A Three B Four C Five D Six

The answer is A. Three.

Here's the step by step explanation:

1. A covalent bond is formed when two atoms share a pair of electrons.

2. In a double bond, two pairs of electrons are shared.

3. Therefore, the two carbon atoms in a double bond share two pairs of electrons.

4. However, the question asks for the number of electron pairs, not the number of bonds.

5. Each bond consists of one pair of electrons, so two bonds consist of two pairs of electrons.

6. Therefore, the number of electron pairs shared by the two carbon atoms in a double bond is two.

7. But, in addition to the two pairs of electrons shared in the double bond, each carbon atom also has a lone pair of electrons.

8. Therefore, the total number of electron pairs shared by the two carbon atoms is three: two from the double bond and one from each of the lone pairs.

So, the correct answer is A. Three.