Relative Atomic Mass and Relative Molecular Mass (2)

Concept of Relative Atomic Mass, RAM (5)

In 1961, carbon-12 atom is used as the standard atom after finding that the usage of hydrogen atom as the standard atom encountered various problems

Concept of Relative Atomic Mass, RAM (6)

The relative atomic mass, RAM of an element is defined as the average mass of an atom of the element compared to 1/12 of the mass of one carbon-12 atom

Reason of carbon-12 is chosen as the standard (1)

Because it is a solid at room temperature and thus can be handled easily

Reason of carbon-12 is chosen as the standard (2)

Carbon-12 combines easily with other elements

Reason of carbon-12 is chosen as the standard (3)

Carbon-12 is found in most substances

Reason of carbon-12 is chosen as the standard (4)

Although carbon has three isotopes, carbon-12 is the major isotope with the abundance of 99%

Reason of carbon-12 is chosen as the standard (5)

The relative atomic mass of carbon-12 exactly 12

Concept of Relative Molecular Mass, RMM (1)

The relative molecular mass, RMM of a molecule is the average mass of the molecule compared to 1/12 of the mass of one carbon-12 atom

Concept of Relative Molecular Mass, RMM (2)

The relative molecular mass of a molecule can be calculated by adding up the relative atomic masses of all the atoms that form the molecule

Concept of Relative Molecular Mass, RMM (3)

Relative molecular mass of a molecule is similar to the total of relative atomic mass of all atoms in the molecule

Chemistry

Question

Relative Atomic Mass and Relative Molecular Mass (2)

Relative Atomic Mass and Relative Molecular Mass (2)