ATOMS MOLECULES AND STOICHIOMETRY

TO BE COVERED• Relative atomic mass• Relative isotopic mass• Relative molecular mass• Relative formula mass

Relative atomic mass

The mass of an atom of an Element compared to the mass of 1/12 of the mass of an atom in carbon-12.

Relative Atomic Mass

Relative Atomic Mass

Relative Atomic Mass

Relative Atomic Mass

Formula:

Relative Atomic MassExamples:

Relative Isotopic Mass

The mass of an atom of an isotope compared to the mass of 1/12 of the mass of an atom in carbon-12.

Formula:

Relative Isotopic MassExamples:

Relative Molecular MassThe ratio of the average mass of one molecule of an element or compound to one twelfth of the mass of an atom of carbon-12.

Formula:

Relative Molecular MassExamples:

Relative Formula MassThe relative formula mass of an ionic molecule is the ratio of sum of the atomic weights of the atoms in the formula of the ionic compound and 1/12th of the mass of one atom of C-12.

Formula:

Formula MassExamples:

Summery

• We did Atomic, Isotopic, Molecular and Formula masses.• Which are relative to s standard “ 1/12th of mass of one

atom of C-12”.

Try it out

• Calculate the molecular masses of : HNO3, H2SO4, AgNO3.

• List out the atomic masses of: Zn, V , Mn , Fe.• Give three examples of elements having isotopes.

Mention them with their isotopic masses.

Thank You