The electronic structure of carbon can be deduced from its atomic number and the arrangement of electrons in its atomic orbitals.
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Atomic Number: Carbon has an atomic number of 6, which means it has 6 electrons.
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Electron Configuration: The electrons are arranged in the following order based on the principles of quantum mechanics (specifically, the Aufbau principle, Pauli exclusion principle, and Hund's rule). The electron configuration of carbon is:
- The first 2 electrons fill the 1s orbital: \(1s^2\)
- The next 2 electrons fill the 2s orbital: \(2s^2\)
- The remaining 2 electrons are placed in the 2p orbitals. Since there are three 2p orbitals (2p_x, 2p_y, and 2p_z), the electrons will occupy these orbitals singly before pairing up, in accordance with Hund's rule. Thus, the configuration for the 2p orbitals is \(2p^2\).
Putting this all together, the complete electron configuration for carbon is:
\[ \text{C: } 1s^2 , 2s^2 , 2p^2 \]
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Electron Shells and Subshells:
- The two innermost electrons are in the first shell (n=1), specifically in the 1s subshell.
- The four outermost electrons are in the second shell (n=2), with two in the 2s subshell and two in the 2p subshell.
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Valence Electrons: Carbon has four valence electrons (2 in the 2s subshell and 2 in the 2p subshell), which makes it tetravalent. This means it can form four covalent bonds with other atoms, contributing to the diverse range of organic compounds it can form.
In summary, the electronic structure of carbon can be represented as:
\[ \text{Electronic Configuration: } 1s^2 , 2s^2 , 2p^2 \]
and it has four valence electrons available for bonding.