Question

21. An element has atomic number $19$ and mass number $39$. How many electrons and protons are present in its unipositive ion?

Answer 1

1. Proton number and atomic number of an atom are the same.
2. An uncharged atom has equal number of protons and electrons.
3. A proton carries a positive charge or $+1$ charge.
4. A electron carries a negative or $-1$ charge.
5. The proton number of the element is $19$.
6. The electron number of the element is$19$.
7. A unipositive ion has $+1$ charge on it.
8. It has one electron less, so the electron number will be- $18$.
9. The proton number will be remain unchanged. It will still be $19$