■ Relative atomic mass based on Carbon-12 scale [modern standard]
► | Definition : The number of times the mass of atom is greater than
of the mass of a carbon-12 atom. Relative atomic mass |
|
► | For example : A magnesium atom is 24 times greater than
of the mass of a carbon-12 atom, thus the relative atomic mass of magnesium is 24. |
|
► | The animation below shows the idea of relative atomic mass in details. |
|
Relative Molecular Mass
■ Relative molecular mass based on Carbon-12 scale
► | Definition : The number of times the mass of a molecule is greater than
of the mass of a carbon-12 atom. Relative molecular mass |
|
► | For example : One nitrogen molecule (N2)is 28 times greater than of a carbon-12 atom, thus, the relative molecular mass of nitrogen is 28. |
■ Calculation of relative molecular mass :
► | Adding the relative atomic masses of all the atoms of the elements forming the molecule. |
✍ Worked-example 3.1(a) Calculate the relative molecular mass for the following elements: (Relative atomic mass : H:1; C:12; N:14; O:16) Solution
|
Relative Formula Mass
■ Relative molecular mass based on Carbon-12 scale
► | Definition : The number of times the mass of an ionic substances is greater than
of the mass of a carbon-12 atom. Relative formula mass |
■ Calculation of relative formula mass :
► | Adding the relative atomic masses of all the atoms of the elements forming the substances. |
✍ Worked-example 3.1(b) Calculate the relative formula mass for the following substances: (Relative atomic mass : H:1; C:12; O:16, Mg:24, S:32, Cl:35.5, Ca:40, Cu:64) Solution:
|
⇲ For exercise(objective and subjective), download for free on Android OS. | ||
Useful
ReplyDelete