Which of the following are true for alpha particles?
I) α particles are equivalent to 2
p+ 2

n.
II) α decay decreases the atomic number by four.
III) α particles are deflected more strongly than e
- by magnetic fields, but in the opposite direction.
IV) α particles are easily stopped as they strike matter.
◦ I and II
◦ I, II, III
◦ I and III
◦ I and IV
◦ I, II, III, and IV