Question

Beryllium has how many valence electrons in its last ring?

Answer 1

Hint: The answer is based on the concept of general chemistry which says that the last ring electrons are nothing but the outermost orbit of the shell of Beryllium atom and this can be known by writing the electronic configuration of the atom.

Complete answer:
We have studied about the basic topic of general chemistry which tells us about the structure and composition of an atom and also about the periodic table and how the atoms are arranged in it.
We shall now see the electronic configuration of the beryllium atom according to the atomic number.
- Atoms are composed of nuclei in which the neutrons and protons are situated together and the negatively charged particles called the electrons revolve around the orbit of the nucleus of an atom.
- The number of protons in an atom is nothing but its atomic number and also always the number of protons is equal to the number of electrons in an atom.
Based on these facts, we can write the electronic configuration of an atom. Now, the electronic configuration of Beryllium atom which has the atomic number 4 with the atomic symbol $Be$ is $1s^{2}2s^2$.
- Here, the outermost shell is 2s and the total number of electrons present in this shell is 2.
Therefore, the correct answer is that Beryllium has 2 electrons in its last ring.

Note:
Note that the electrons that are present in the outermost orbit of any atom or the electrons present in the last ring of any atom are called the valence electrons and these electrons are capable of forming a chemical bond if the outermost shell is not closed.