Identify the reason why atoms lose, gain or share electrons in a chemical reaction.

Atoms lose, gain, or share electrons in a chemical reaction in order to achieve a stable electron configuration. This is often referred to as the "octet rule," which states that atoms are most stable when their outermost electron shell is full, typically with eight electrons.

Here are the steps:

1. Atoms are made up of protons, neutrons, and electrons. The protons and neutrons are located in the nucleus of the atom, while the electrons orbit the nucleus in energy levels, or shells.

2. The first shell can hold up to 2 electrons, and the second and third shells can hold up to 8 electrons each. The outermost shell of an atom is called the valence shell, and the electrons in this shell are called valence electrons.

3. Atoms are most stable when their valence shell is full. This is because a full valence shell reduces the potential energy of the atom, making it less likely to react with other atoms.

4. If an atom's valence shell is not full, it will try to fill it by losing, gaining, or sharing electrons with other atoms. This is what drives chemical reactions.

5. For example, in the reaction between sodium (Na) and chlorine (Cl) to form sodium chloride (NaCl), sodium loses one electron to chlorine. This allows sodium to have a full valence shell (by dropping down