Question

Choose the correct option for proton:
A.It is a nucleus of deuterium
B.It is an ionised hydrogen atom
C.It is ionised hydrogen molecule
D.It is an $\alpha $ particle

Answer 1

Hint: The nucleus of an element contains protons and neutrons of specific numbers. These particles are generally called subatomic particles as they are sub-part of an atom.
-The electrons are present outside the nucleus, and are held together by attractive forces of the proton, which is present inside the nucleus.

Complete answer:
Proton is a subatomic particle which is present inside the nucleus of an atom it has a positive electric charge of elementary charge and the mass of a proton is slightly less than that of a neutron. Protons and neutrons are collectively termed "nucleons". The number of protons in the nucleus of every atom is one or more. The protons are a necessary part of the nucleus. The number of protons in the nucleus defines the properties of an element, and is usually termed as the atomic number. Since each element has a specific and unique number of protons, each element has its own unique atomic number.
If we consider the options given in the question, we can see that the deuterium is option A. we know that Deuterium is one of the stable isotopes of hydrogen. Isotope meaning, the element having the same number of protons, but different number of neutrons. The isotope of hydrogen, that is deuterium, has one proton and one neutron in the nucleus. This is a reason, it is also termed as heavy hydrogen.
If we consider the second option, we know that ionisation is a process in which the electrons present in an element are pulled out of the atom, or in other words, when an element loses its electrons, the process is called ionisation. Option B, says the proton is an ionised hydrogen atom. The hydrogen atom contains one proton and one electron. And after ionisation it loses that electron, hence only the proton is left.
Option C, says the ionised hydrogen molecule. Now we all know that a hydrogen molecule contains two atoms of hydrogen, and ionisation of it will still leave one electron in the molecule, along with two protons. So this option is not correct.
Option D, says alpha particle. And we all know that the $\alpha $ particle contains two protons and two neutrons, it is basically a helium nucleus. Since it contains two protons, this option is not appropriate.
And hence option B is the correct answer.

Note:The proton or the positive hydrogen ion, does not exist as ${{H}^{+}}$ in aqueous solution, in fact, it exists as hydronium ion that is \[{{H}_ {3}} {{O}^ {+}} \].

-Deuterium is a stable isotope of hydrogen which contains one proton and one neutron; the ionised hydrogen atom is also called proton because it contains only one proton and no electrons; ionised hydrogen molecule is not a proton as it is derived from two molecules of hydrogen and one electron is still left in the molecule after ionisation; an alpha particle is not a proton it is a positively charged helium atom.