If you were to add a proton to a neutral atom what would change

It would change the charge, a neutral atom has zero charge but a proton has a positive charge.  So 0 charge + 1 positive charge = 1 positive charge.

i am going to put the answers in order i dint feel like typing it out so yeah

a

d

c

b

b

b

a

d

a

b

c

c

c

b

d