Question 3 (1 point)
Choose the letter of the correct name for each structure.
CH3CH2C=CCH3
a 3-pentane
2-pentyne
4-pentyne

Full question:

The IUPAC name for  CH3CH2C≡CCH3 is:

2-pentyne

Explanation:

To name hydrocarbons, you first you have to identify the longest carbon chain.  There are 5 carbons in this chain, so we know the name is "pent".

You then have to identify the presence of any double or triple bonds. If double bonds, it is an alkene, if triple bonds, it is an alkyne. In this case there is a triple bond, so we know the hydrocarbon is pentyne.

You then number the chain to give the lowest number to the triple bond. It could either be 4 (countnig carbons from left to right) or 2 (from right to left). Therefore, the answer is 2-pentyne.

it means there are 3 atoms of oxygen