Question

The mass number of an element is 39 and it has 20 neutrons. The atomic number of the element is

Answer 1

Answer:

it's 19

proton 20

name potassium

neutron 20

Answer 2

Answer:

19

Explanation:

as mass no. = no. of neutron + no. of proton

so ... let atomic no be x

39 = 20 + x

x= 19

hope it helps..