An alpha particle consists of two protons and two
neutrons. what is the charge of an alpha particle?
(1) 1.25 × 10^19 c (3) 6.40 × 10^–19 c
(2) 2.00 c (4) 3.20 × 10^–19 c

     The Elementary Charge is given by:


 
     In the alpha particle there are two protons, so the total charge will be:


 
     Remember that the neutron has no charge, therefore not appear in the calculation.

Number 4
  
If you notice any mistake in my english, please let me know, because i am not native.

F = ma

F = 2 * 15

F = 30 N

hopes this helps u