Question

Select the correct answer.

Answer 1

Answer:

i think 10 because

atomic number (p^+) =10

atomic mass (e^-) = 20

atomic no =(p^+) =(e^-)=10

(p^+)=10

(e^-)=10

again

atomic number= (p^+) + (n^0)

20 = 10 +n^0)

20-10 =n^0

n^0= 10