How many electrons are unpaired in the orbitals of carbon?
a. 12 electrons
b. 2 electrons
c. 4 electrons
d. 6 electrons
The correct answer and explanation is:
The correct answer is b. 2 electrons.
Explanation:
Carbon has an atomic number of 6, meaning it has 6 electrons. These electrons are arranged in orbitals around the nucleus, following the principles of quantum mechanics, which include the Aufbau principle, Pauli Exclusion principle, and Hund’s rule.
The electron configuration for carbon is:
1s² 2s² 2p².
This configuration shows that the first two electrons fill the 1s orbital, the next two fill the 2s orbital, and the remaining two electrons go into the 2p orbitals. The 2p orbitals can hold a maximum of six electrons, but in the case of carbon, they only hold two electrons.
According to Hund’s rule, when electrons occupy degenerate orbitals (orbitals of the same energy level, like the three 2p orbitals), they will first fill them singly with parallel spins before pairing. This results in two unpaired electrons in the 2p orbitals of carbon. These two electrons occupy two of the three 2p orbitals, each with a single electron.
So, in summary, carbon has two unpaired electrons in its 2p orbitals. These unpaired electrons play a critical role in carbon’s ability to form covalent bonds, such as in the creation of organic molecules. This ability to bond with other atoms, including forming double and triple bonds, is a key reason why carbon is so important in biological and chemical processes.