Question

An element ‘X’ has six electrons in its outer or valence shell.

Its valency is___________(+2,-2,-1)

Answer 1

Understanding the concept: The distribution or arrangement of electrons into an atom's orbitals is known as electronic configuration.

• The number of electrons present in the outermost shell are called valence electrons.
• The number of electrons that participate in bond formation is called valency.
• As per the octet rule, to complete the octet it needs two electrons.

The explanation of valencies:

• +2 is the valency in which the total number of electrons in the outermost shell is equal to 2.
• For example, Calcium loses the outer two valence electrons and attains a valency of +2.
• +1 is the valency in which the total number of electrons is equal to one and loses this electron.
• For example, sodium has 1 electron in its outermost shell and it will lose this electron ad attains a valency of 1.
• -2 is the valency in which the total number of electrons in the outermost shell is equal to 6. For example, the element sulfur contains 6 valence electrons in the outer shell, which will gain two 2 electrons, and attain a valency of -2.

Thus An element ‘X’ has six electrons in its outer or valence shell, Its valency is -2