Oxygen has ____________ electrons in its outermost ___________ shell.

Correct option is B

The correct answer is (B)

Explanation:

Oxygen is an element with the atomic number 8, which means it has 8 protons and, in a neutral atom, 8 electrons. These electrons are arranged in shells around the nucleus following the rules of electron configuration:

• First shell (K-shell): The first shell can hold a maximum of 2 electrons. Oxygen's first 2 electrons fill this shell.
• Second shell (L-shell): The remaining 6 electrons occupy the second shell, which is the outermost or valence shell.

Since the valence shell of oxygen is the second shell, it has 6 electrons in it. These electrons determine the chemical properties of oxygen, such as its tendency to form bonds by gaining 2 more electrons to complete its octet (a full outer shell with 8 electrons). This is why oxygen typically forms two covalent bonds in molecules like water (H_2O) or oxygen gas (O_2​).

Information Booster:

1. Valency:

• Definition: The valency of an element is the number of electrons it needs to gain, lose, or share to achieve a full outermost shell (usually 8 electrons, following the octet rule).
• Oxygen's Valency: Oxygen has 6 electrons in its outermost shell and needs 2 more electrons to complete its octet. Therefore, its valency is 2.

2. Valence Electrons:

• Definition: Valence electrons are the electrons in the outermost shell of an atom that are involved in chemical bonding.
• Oxygen's Valence Electrons: Oxygen has 6 valence electrons because its outermost (second) shell contains 6 electrons.

3. Valence Shell:

• Definition: The valence shell is the outermost electron shell of an atom that contains valence electrons.
• Oxygen's Valence Shell: For oxygen, the second shell is the valence shell, and it holds the 6 valence electrons.