I have read the info on testing caps. How can I tell if I have an electrolytic cap?

I have a 35 μF capacitor.

New to this. Thanks.

 

Does the capacitor have a polarity marked on it? We could tell more from a photo, although the capacity almost makes it certain that it is.

 

Read part number on part. Type said number into google.com. Or digikey.com. Or FindChips.com. Follow link to data sheet.

Read the data sheet.

If no part number on part or search returns no hits then dispose of said equipment in an environmentally responsible fashion.

 

it basically comes down to the physical form factor

electrolytic and the newer "alum-alytic" caps look like soda cans basically.

 

If its an electrolytic capacitor, it will have a polarity markings on in, looking like a can as seen on picture.

The longer end is + terminal and shorter pin is the negative terminal.