Question

1. what element is present in all organic molecules? (1 point)

○ carbon.
○ helium.
○ oxygen.
○ iron.

Explanation:

Organic molecules are defined as compounds containing carbon (except some simple carbon - containing compounds like carbonates, cyanides, etc. which are inorganic). Helium is a noble gas, oxygen is not in all organic molecules (e.g., methane has no oxygen), and iron is a metal not in all organic molecules. So carbon is present in all organic molecules.

Answer:

A. Carbon.