Question: how many hydrogen atoms are there in cyclooctane?
Answer: Each molecule in the Cyclooctane/Octane Cycle sequence has 8 carbon atoms (C). The sequence starts with the simplest possible 8 carbon molecule: n-octane (octane) which consists of 8 carbon atoms bonded to one another in a straight line. (Hydrogen atoms are also present but are not depicted in the SMILES format above.)