Question

The electrons present in the outermost shell of an atom are known as:
(A) Protons
(B) Neutrons
(C) Octet
(D) Valence electrons

Answer 1

Hint: An atom consists of three basic particles which are protons, electrons, and neutrons. The atom is the smallest particle in which protons and neutrons are present in the center and electrons revolve around it. Electrons revolve around the nucleus in certain definite paths called orbits or shells.

Complete answer:
The structure of an atom is as shown below:

As stated in the Bohr’s model of an atom, electrons travel in a definite circular orbit also known as shells. In addition to this, the last orbit is known as the outermost shell. If the outermost shell is completely filled with electrons then it is a noble gas.
If the outermost shell is partially filled with electrons then it becomes a valence shell. The electrons present in the valence shell are known as valence electrons.
The valence electrons which are present in the outermost shell participate in the compound formation. An atom achieves stability either by donating valence electrons or by accepting extra electrons from another atom. This is done in order to gain the stable configuration or basically to complete the octet.
Thus, the electrons present in the outermost shell of an atom are known as valence electrons.

So, the correct choice is (D).

Note: The atoms don’t achieve stability only by donating or accepting the valence electrons. Sometimes stability is achieved from various types of bonds by sharing the electrons. A chemical bond is basically the force of attraction between any two atoms in a molecule required to maintain stability. These various types of bonds are covalent bond, triple bond, hydrogen bonding, ionic bond, polar covalent bond, metallic bond, etc. In a group there are the same number of electrons in the outermost shell.