Yes: Carbon can gain 4 electrons from less electronegative elements to form a carbide ion with a charge of -4 in an ionic compound. (More often, however, a carbon atoms will share four electrons with other atoms to form covalent bonds.)
gain
net gain of carbon atom is 8 in kreb cycle
autotrophs gain carbon via CO2. Heterotrophs gain carbon by consuming organic molecules.
4
carbon dioxide
Carbon needs to either gain 4 electrons or lose them. This is extremely difficult and energetically unfavorable. It is far easier to share them instead.
The only way a carbon atom becomes stable is if they gain or lose electrons. Typically carbon will bond with other elements to do this.
carbon has 4 electrons in valence shell. In order to form ionic compound, carbon should either gain four electrons or lose four electrons; both of which required high energy and is not easy. so carbon will share its electrons by forming covalent bond and gain stability.
by sharing its electrons
Carbon can both gain and lose electrons. We "see" it every day in the form of compounds or in pure substance.
An element that has two outer electrons is carbon. Carbon would not use the energy to gain six more electrons when it can easily get rid of the two outer electrons.
Yes, true. Carbon has 4 valence electrons. Therefore, it is harder to to lose and gain 4 electrons. So it simply shares.