Question

The simplest atom that does not contain neutron is
A.Deuterium
B.Tritium
C.Hydrogen
D.Helium

Answer 1

We must remember that an atom is a very small component of an element, which has the chemical properties of the element. The word atom means indivisible, atomos in Greek. Democritus, a Greek philosopher, first used the word atomos. Atom is made up of three main particles called neutrons, protons and electrons.

Complete step by step answer:
We must remember that an atom consists of neutrons, protons and electrons, in these, protons and electrons are charged particles, protons are positively charged due to protons and electrons are negatively charged but neutrons are neutral particles. We must remember that the protons and neutrons are in the nucleus whereas electrons are revolving around the nucleus in an atom. Atoms have atomic numbers and atomic mass. Atomic number is the number of protons or electrons and atomic mass is the sum of protons or electrons and neutrons.
Let us see the given options to seek out the correct options.
Option a. Deuterium
We need to remember that the deuterium is an isotope (same atomic number but different atomic mass) of hydrogen. Deuterium atomic number is one and the atomic mass is two, contains one proton and one neutron. So this is not the simplest atom. Therefore, the option A is incorrect.
Now we discuss about the option B as, Tritium
We need to know that another isotope of hydrogen is tritium (chemical symbol is ). Tritium atomic mass is three, indicates two neutrons and one proton. Tritium contains neutrons. Hence, this is not the right option.
Option c. Hydrogen
As we know that hydrogen is the first element in the periodic table. Hydrogen atomic number is one and also atomic mass is one. Hydrogen atomic mass one shows that hydrogen contains only protons. So hydrogen is the simplest atom.
Option d. Helium
Helium atomic number is two and atomic mass is four suggest that helium has two neutrons. So helium is not the simplest atom.
From the above discussions, we can conclude that hydrogen is the simplest atom and does not contain neutrons.
So, Option c. Hydrogen is the correct option.

Note:
We have to remember that if we add or remove the proton from the nucleus of an atom changes the atomic number and also changes properties. But removing or adding a neutron does not change the atomic number but sometimes it creates isotopes. But adding or removing the protons or neutrons from the nucleus is not an easy process.