Question

The charge on the atom containing 17 protons, 18 neutrons and 18 electrons is:
A.$ + 1$
B.$ - 2$
C.$ - 1$
D.Zero

Answer 1

Hint: To solve this question, you must be familiar with the subatomic particles, namely electrons, neutrons and protons. Neutrons are neutral particles and do not carry a charge.

Complete step by step solution:
Protons are subatomic particles which weigh equal to one atomic mass unit and carry a single positive charge.
Neutrons are particles with mass almost equal to that of a proton but it is electrically neutral.
Electrons are particles with negligible mass as compared to protons and neutrons but they carry a single negative charge.
The mass of the atom is considered equal to the mass of the nucleus as the mass of electrons is negligible in comparison to the mass of protons. Whereas, the charge of the atom is solely determined by the electrons and protons in the atom.
In the question, the number of protons is 17 and the number of electrons is 18.
Since, there is an extra electron in the atom, it carries a charge of $ - 1$ .

So, the correct answer is C.

Note:
An atom of each element contains a fixed number of protons. In other words, we can say that the number of protons determines the atom we are considering. We are familiar with the fact that the number of protons in an atom is called the atomic number of an atom. If we change the number of protons, the element we are considering changes. Unlike the number of protons, the number of neutrons and electrons for a certain element can vary. If the number of neutrons in an atom varies keeping the number of protons equal, we obtain isotopes. While if the number of electrons in an atom changes, we obtain ions. If the atom gains an electron we get an anion and if it loses an electron we get a cation.