How many valence electrons are in a Neutral atom of Magnesium?
The correct answer and explanation is:
Correct Answer: A neutral atom of magnesium has 2 valence electrons.
Explanation:
Valence electrons are the electrons found in the outermost energy level (shell) of an atom. These electrons are important because they determine how an element reacts chemically with other substances.
Magnesium is a chemical element with the symbol Mg and an atomic number of 12. This means a neutral magnesium atom has 12 protons in its nucleus and 12 electrons orbiting around the nucleus. These 12 electrons are arranged in specific energy levels or shells according to the principles of electron configuration.
The electron configuration of magnesium is:
1s² 2s² 2p⁶ 3s²
This configuration tells us that:
- The first shell (1s²) holds 2 electrons
- The second shell (2s² 2p⁶) holds 8 electrons
- The third shell (3s²) holds 2 electrons
The outermost shell for magnesium is the third shell, and it contains 2 electrons in the 3s orbital. These are the valence electrons.
Valence electrons play a key role in bonding. For example, magnesium tends to lose its two valence electrons to achieve a stable electron configuration similar to the noble gas neon (which has a full second shell). When it loses these two electrons, magnesium becomes a positively charged ion (Mg²⁺), which is commonly found in compounds like magnesium oxide (MgO) or magnesium chloride (MgCl₂).
In summary, a neutral magnesium atom has 2 valence electrons, located in the 3s orbital of the third energy level. These electrons are responsible for magnesium’s chemical properties and its ability to form bonds by donating them.