Question

what is molecular formula? what is valency ? give example​

Answer 1

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. ... For example, oxygen has six valence electrons, but its valency is 2. Some elements may have more than one combining power (or valency), while others have just one.

For example, the molecular formula of butene, C4H8, shows that each freely existing molecule of butene contains four atoms of carbon and eight atoms of hydrogen. Its empirical formula is CH2. One molecule of ethylene (molecular formula C2H4) contains two atoms of carbon and four atoms of hydrogen.

Answer 2

molecular formula

When atoms of one element combine with the atoms of another element to form formula units, they do so in fixed numbers depending upon the capacities of the atoms to form bonds. Valency of an element is a measure of the combining capacity of its atom to form chemical bonds.

Valency A measurement of the power of an atom to combine with others, by the number of hydrogen atoms it can combine with or take the place.

Example- Ch4 methane