How many valence electrons does the positively charged carbon atom have?
The Correct Answer and Explanation is:
Correct Answer: A positively charged carbon atom (C⁺) has 3 valence electrons.
Explanation:
In chemistry, understanding the number of valence electrons is crucial for predicting an element’s reactivity, bonding behavior, and the structure of molecules. Valence electrons are the electrons found in the outermost electron shell of an atom. For carbon, which is located in Group 14 of the periodic table, the neutral atom has 4 valence electrons. The electron configuration of a neutral carbon atom is:
1s² 2s² 2p²
The valence electrons are those in the second energy level: 2s² and 2p², totaling 4 electrons.
However, when carbon becomes positively charged—meaning it has lost one electron—its electron configuration changes. A C⁺ ion has one fewer electron than the neutral carbon atom. Therefore, one electron is removed from the outermost shell, reducing the number of valence electrons.
If one valence electron is removed, the new configuration becomes:
1s² 2s² 2p¹
This totals 3 valence electrons: two in the 2s orbital and one in the 2p orbital.
This positively charged state is often seen in organic chemistry, particularly in the formation of carbocations. A carbocation is a carbon atom that has lost one of its valence electrons, resulting in a positive charge and an electron-deficient structure. This makes it highly reactive and important in mechanisms like nucleophilic substitution and electrophilic addition.
In summary, a positively charged carbon atom (C⁺) has 3 valence electrons because it has lost one from its original 4 in the neutral state. This deficiency in electrons creates a highly reactive intermediate, which is essential in many chemical reactions.
