write the systematic name of each organic molecule: structure name 2,5 - dihydroxpentana

Explanation:

Step1: Identify the longest carbon - chain

The longest carbon - chain has 6 carbon atoms.

Step2: Identify the functional groups

There is an aldehyde group ($-CHO$) at the end of the chain, so it is an aldehyde. The numbering should start from the carbon of the aldehyde group.

Step3: Name the substituents

There is a methyl group at the 3 - position.

Answer:

3 - methylhexanal