Is it possible for an electron to slow down to zero velocity?

Question

What happens to it if it does slow to zero velocity?

Answer 1

no an electron has a rest mass of Zero. I.e. it will shed all its energy in slowing down. I n fact it will most likely be absorbed by a nucleus, where it will interact with a neutron, emit an anti neutrino and a proton.  

Answer 2

Of course an electron has a rest mass but it can't be slowed down to exactly zero because of the heisenberg uncertainty principle.