how can i export a whole category?
Have you read the article Product export from Knowledge base?
It’s quite clear.
ok so the answer is no
The answer is yes.
go to categories, where you see the category you want to export look to the right and you will see a numder with a + to the side of it.
Click that number then all products in that category appear.
select all chackboxes at the left side then at the bottom of page select drop down arrow and select export slected.
You can also do this similar thing form the export window itself.