The number of protons in an atom of an element A is 17 then, the number of electron in its ion A- is:
A. 18
B. 19
C. 20
D. 21
Answer:A
The number of protons in an atom of an element A is 17 then, the number of electron in its ion A- is:
A. 18 B. 19 C. 20 D. 21
Explanation: In the neutral atom of an element