Why does one carbon atom bond with four hydrogen atoms have a covalent bond?
A covalent bond forms between one carbon atom and four hydrogen atoms because they share electrons in order to achieve a more stable electron configuration.
Carbon has four valence electrons, meaning it requires four additional electrons to achieve a stable octet (eight electrons in its outermost energy level). Hydrogen, on the other hand, has one valence electron and requires one additional electron to achieve a stable configuration with two electrons.
To satisfy the electron needs of both carbon and hydrogen, the carbon atom shares one electron with each of the four hydrogen atoms. This sharing of electrons allows carbon to complete its octet and hydrogen to achieve a stable configuration with two electrons.
In this covalent bond, each hydrogen shares its one electron with carbon, and carbon shares its four valence electrons with the four hydrogen atoms. By sharing electrons, both carbon and hydrogen attain a more stable electronic arrangement, fulfilling the octet rule.