Question

How many electrons does a hydrogen atom have?

Answer 1

Hint The atomic number of hydrogen is 1. The atomic number is related to the number of electrons and protons present in an atom.

Complete step by step solution:
So in the question, it is asked how many electrons a hydrogen atom has. So before solving the question, let’s have an idea about the atomic number and mass number so that it will help us in calculating the number of protons, electrons and neutrons present in an atom.
We know that in the periodic table the elements are arranged according to the increasing order of their atomic number.
Atomic number of an element is the unique number or can be said as the identity of an element and now two elements in the periodic table will have the same atomic number. The atomic number of an element gives the number of electrons and protons present in the atom.ie the atomic number will be equal to the number of electrons and number of protons.
Now we should know about another parameter which is atomic mass. Atomic mass is the sum of the number of protons and number of electrons present in the atom. We know that both the species i.e. protons and neutrons are present in the nucleus so we could say that the weight of the nucleus accounts for the atomic mass of the atom.
Let’s move on to the solution part of the question. We are concerned about the number of electrons a hydrogen atom has.
We know H is the first element in the periodic table and hence its atomic number is 1.
If the atomic number is 1, then it means that there is one proton and one electron in the H atom.

So this gives us the final answer, there is only one electron present in the shell of the H atom.

Note: If in the question the number of electron in deuterium and tritium was asked then also, the number of electrons will be same i.e. there will be only one electron in both of them since deuterium and tritium are the isotopes of H. The isotopes differ only by the mass number and not by atomic number so they will only differ by the number of neutrons in them.