Answer:
4
Step-by-step explanation:
A carbon atom can form covalent bonds with four hydrogen atoms because each hydrogen atom needs one electron to achieve stability. We know that carbon atom has four electrons in its outermost shell so four hydrogen atoms are needed to get stability to both carbon and hydrogen. If there is another atom that needs two electrons to attain stability so the carbon atom can form bond with two atoms because no extra electron is available for pairing.