What are branched chain and cyclic alkanes?

Question 1

What are branched chain and cyclic alkanes?
Straight-chain alkanes have carbon atoms that are connected to each other in one continuous chain, e.g. butane

Branched chain alkanes
These alkanes have

Answer 1

side groups attached to the main carbon chain, e.g. 2-methylbutane

is a branched organic molecule as the main chain (consisting of 4 carbon atoms) has a methyl branch

Question 2

To name branched chain alkanes:

Answer 2

Identify the longest carbon chain and assign the corresponding alkane prefix

Longest carbon chain = 4 carbons so the prefix is but-.
Check all of the carbon-carbon bonds are single and assign the appropriate suffix

All carbon-carbon bonds are single so the suffix is -ane.
Identify any side chains / branches

There is a methyl / CH3 group on carbon 2, which gives 2-methyl-.
Combining all of these fragments gives the overall 2-methylbutane name.