Question

The complicated molecules that make up living things usually contain carbon. Why is carbon so important in these molecules?
A. Carbon can form four strong covalent bonds.
B. Carbon can only form one bond at a time.
C. Carbon forms ionic bonds with most elements.
D. Carbon is the lightest and smallest element.

Answer 1

A
The strong, stable and high number of bonds that carbon can form make it an essential element in organic molecules. 

Answer 2

Answer;

A. Carbon can form four strong covalent bonds.

Explanation;

Carbon can form up to 4 covalent bonds, and it can form reasonably strong bonds with nitrogen, oxygen, and other heteroatoms.

Carbon also has an almost unique ability to catenate: to form long chains with

C − C linkages, and along the chain there can be regions of different reactivity (by the presence of functional groups).