Answer the following question given this paragraph: 

Alkenes can have different shapes. They can form straight chains, branched chains, or rings. Alkenes with the same atoms but different shapes are called isomers. Smaller alkenes have relatively high boiling and melting points, so they are gases at room temperature. Larger alkenes have lower boiling and melting points, so they are liquids or waxy solids at room temperature.


Q: Alkenes with the same atoms but different shapes are called what?

 Choices:

- alcohols

- monomers

- isotopes

- isomers

A:
isomers
