What's the difference between...

...empathic and empathetic please?

I know it sounds like a joke and you might be sat/stood/laid there, scratching your head, trying to work out where the humour is, but it's an honest, genuine question that I can't work out the answer to.

If you know the answer, could you explain it to this dumbo in the comments so that I can go back to it in future when I forget pretty please?

Thank you!