How many double covalent bonds can be formed by one carbon atom?

It depends on the element Following what one might call "normal" valence an atom such as carbon can form up to 4 bonds. But in some compounds, such as sulfur hexafluoride and atom can bond with as...

Since a carbon atom has four valence electrons, it can bond with a maximum of four atoms, (e.g. methane or CH4).

Two covalent bonds attach both Oxygen atoms to the Carbon atom. You should have figured that out using the Lewis structure.

It depends on the number of valence electrons.

Carbon generally form four covalent bonds. Carbon has six electrons. Two of its electrons completely fill the first shell while the remaining four leave the second shell halfway full. Therefore,...