What is the correct symbol of an ion containing 17 protons,20 neutrons and 18 electrons

The symbol of the ion is A^-

Explanation:

Let A be the symbol of the element.

Proton = 17

Electron = 18

Neutron = 20

Since the element has more electrons than protons, it means it has gain electrons.

From the question given,

The difference between the electron and proton = 18 — 17 = 1

So, the element has gain 1 electron.

Therefore the symbol of the ion is A^-

answer: -

reaction:

na + cl ⇌ nacl

balanced chemical equation:

na + 2cl ⇌ nacl2

sodium + clorine goes to form sodium chloride (table salt).

the product is nacl2.

and the reactants are na and cl.

(note: if you don’t know what ⇌ means, read below: -

⇌(double head arrow) means reversible reaction).

the answer is option a.