Carbon has four electrons in its outer electron shell, therefore: Select one: a. it has a filled outer electron shell. b. it can form four single covalent bonds c. it does not react with any other atoms. d. it has a positive charge.

B

Explanation:

Carbon is an element with an atomic number 6, the electron configuration is 2,4. This means it has four electrons in its outer-most shell or valence shell. The valence shell needs 8 electrons to be filled. Thus the outer electron shell of carbon is unfilled.

It reacts with other elements covalently and forms organic and in-organic compounds.

The 4 electrons in the valance shell of carbon makes it a metalliod, but commonly its considered as a non-metal.

However carbon can form single and double covalent bonds. It forms single covalent bond when it combines with 4 atoms of Hydrogen in the methane molecule