Fatty acids do not have a fixed number of carbon atoms. They can vary in chain length, which means they can have different numbers of carbon atoms.

Here's what you need to know about fatty acids and their carbon chains:

* Short-chain fatty acids: Have 4-6 carbon atoms.

* Medium-chain fatty acids: Have 6-12 carbon atoms.

* Long-chain fatty acids: Have 12-24 carbon atoms.

* Very long-chain fatty acids: Have 24 or more carbon atoms.

So, it's incorrect to say all fatty acids have a specific number of carbon atoms. They vary depending on the type of fatty acid.