(a) What is the general name of all the compounds made up of carbon and hydrogen?
(b) Why does carbon form compounds mainly by covalent bonding?
(a) The general name for all the compounds made up of hydrogen and carbon is hydrocarbons.
(b) Carbon has the property of tetravalency, so it mainly forms covalent bonds. Since carbon is an element with atomic number 6, its electronic configuration is (2,4). This means there are 4 valence electrons in its outermost shell, and it can either gain 4 electrons or lose 4 electrons to attain the inert gas configuration for becoming stable. As the atoms of carbon are of an extremely small size, the nucleus exerts a great force of attraction on the outermost electrons to hold them tightly. This makes it difficult to remove or add electrons to its structure. Therefore, it attains the inert gas configuration by the sharing of electrons in the outermost shell. As the inert gas configuration is attained by the sharing of electrons, carbon forms compound always by covalent bonding.