Question

The valency of an element can be expressed as:

• A. the mass of the element displacing 1 part by the mass of hydrogen.
• B. the mass of the element combining with 8 parts by mass of oxygen.
• C. the number of atoms of hydrogen combining with 1 atom of the given element.
• D. the number of atoms in 1 molecule of the given element.

Answer 1

Answer: (C)

the number of atoms of hydrogen combining with 1 atom of the given element.

The valency of an element is the number of hydrogen atoms that can combine with or replace (either directly or indirectly) one atom of the element. In other words, the valency of an element is the number of electrons an atom of the element uses to combine with atoms of other elements - it is the combining power of an atom of the element. In an atom, the valence electrons are the electrons that can be used in combining with other atoms - these are the electrons in the orbitals of the outermost shell (also called valence shell).

Hence, the correct option is $\text{C}$