A carbon atom does not form a C- anion and C+ cation because:
a) It lacks electrons for an anion
b) It cannot lose or gain electrons easily
c) Its atomic number is low
d) It is a noble gas
The Correct answer and Explanation is:
The correct answer is b) It cannot lose or gain electrons easily.
Explanation:
A carbon atom, with an atomic number of 6, has the electronic configuration of (1s^2 2s^2 2p^2). This configuration means that it has four electrons in its outer shell (the second shell), which can accommodate up to eight electrons according to the octet rule. Carbon typically forms covalent bonds by sharing these electrons with other atoms, allowing it to achieve a stable octet configuration.
When considering the formation of ions, we analyze the likelihood of gaining or losing electrons. For carbon to form a C⁻ anion, it would need to gain four additional electrons. However, carbon is situated in the second period of the periodic table and is not highly electronegative. This means it does not have a strong tendency to attract additional electrons. Gaining four electrons would not only require a considerable amount of energy, but also the stability of such an anion would be highly unfavorable due to the repulsion of the added electrons.
On the other hand, to form a C⁺ cation, carbon would need to lose four electrons. Losing four electrons would lead to a highly unstable configuration, as it would result in a bare nucleus that no longer has its stable electronic structure. Generally, non-metals, such as carbon, prefer to gain or share electrons rather than lose them, as losing electrons can destabilize their configuration.
Additionally, carbon’s ability to form strong covalent bonds with other atoms makes it unlikely to exist as an isolated ion in its common chemical interactions. The stability of covalent compounds involving carbon—like hydrocarbons—illustrates its preference for sharing electrons rather than forming charged species.
In summary, carbon does not readily form C⁻ or C⁺ ions primarily because it cannot lose or gain electrons easily, reflecting its position in the periodic table and its tendency to form covalent bonds instead.