Question

An element X has 19 protons and 39 nucleons. Another element Y has an atomic number= 17.​

Answer 1

Answer:

X has 19 protons. so, it's atomic number is 19.

X is Potassium (K).

Y has an atomic number= 17.So, it is Chlorine (Cl).

hope the answer helps.

Answer 2

Answer:

hope it helps you too understand

for element x

protons 19  and atomic mass is 39

No. of Neutrons = Mass No. - Atomic No  

no. of  neutrons = 39 - 19

no. of  neutrons =20

for element y

atomic no is 17

so atomic no = no protons 17

and we know that the mass of atomic no 17 is 35.4

so, No. of Neutrons = Mass No. - Atomic No

no. of  neutrons =35.4-17

no. of neutrons = 18.4