How to calculate atomic mass of an element ?
How to calculate atomic mass of an element ?
Atomic Mass:
The sum of the Masses of protons, neutrons, and electrons in an atom is the Atomic Mass. In contrast with protons or neutrons, the electrons have much less Mass, so the Mass of electrons is neglected in the calculation.
Atomic Mass formula = Mass of protons + Mass of neutrons + Mass of electrons
The relative Atomic Mass of an element is the total Mass of the element's naturally occurring isotopes relative to the Mass of a 12C atom which means a relative Atomic Mass of exactly 12 is given to one atom.
Calculate the Atomic Mass:
There are two ways to calculate the atomic mass of an element
(1) By Addition of Protons and Neutrons:
If we want to calculate the atomic number of a single atom of an element. we need to add the number of neutrons and protons in an atom.
For example, the Nitrogen atom has 7 neutrons and 7 protons,
The atomic mass of Nitrogen = 7 + 7 = 14
so its atomic number will be 14amu. amu or u is the unit for atomic masses.
(2) Calculation of the Average Atomic Mass:
The average Atomic Mass of various elements is determined by multiplying the Atomic Mass of each isotope by its fractional abundance and adding the value obtained.
For example, chlorine contains two types of atoms having relative Masses of 35u and 37u. The relative abundance of these isotopes in nature is in the ratio of 3:1.
Therefore, the Atomic Mass of chlorine is the average of these different relative Masses.
Thus, the formula of the average Atomic Mass of chlorine = (35×3)+(37×1)4=35.5u
Atomic Mass:
The sum of the Masses of protons, neutrons, and electrons in an atom is the Atomic Mass. In contrast with protons or neutrons, the electrons have much less Mass, so the Mass of electrons is neglected in the calculation.
Atomic Mass formula = Mass of protons + Mass of neutrons + Mass of electrons
The relative Atomic Mass of an element is the total Mass of the element's naturally occurring isotopes relative to the Mass of a 12C atom which means a relative Atomic Mass of exactly 12 is given to one atom.
Calculate the Atomic Mass:
There are two ways to calculate the atomic mass of an element
(1) By Addition of Protons and Neutrons:
If we want to calculate the atomic number of a single atom of an element. we need to add the number of neutrons and protons in an atom.
For example, the Nitrogen atom has 7 neutrons and 7 protons,
The atomic mass of Nitrogen = 7 + 7 = 14
so its atomic number will be 14amu. amu or u is the unit for atomic masses.
(2) Calculation of the Average Atomic Mass:
The average Atomic Mass of various elements is determined by multiplying the Atomic Mass of each isotope by its fractional abundance and adding the value obtained.
For example, chlorine contains two types of atoms having relative Masses of 35u and 37u. The relative abundance of these isotopes in nature is in the ratio of 3:1.
Therefore, the Atomic Mass of chlorine is the average of these different relative Masses.
Thus, the formula of the average Atomic Mass of chlorine = (35×3)+(37×1)4=35.5u
