How is the atomic mass of element in decimals,although its formula is given by no of protons +no of neutrons?
Dear student
Please find the solution to the asked query:
Atomic mass is the average of all the isotopes of the element.
But the naturally occurring isotopes of chlorine Cl 35 (75.77%) and Cl 37(24.23%) are relatively present in the ratio 3:1 quite large amount than other elements, hence giving chlorine atomic mass 35.45 approximately 35.5 .
The abundances of the isotopes present in the elements are multiplied by the atomic masses in which they are present.
Hope this information will clear your doubts regarding the topic. If you have any other doubts please ask here on the forum and our experts will try to solve them as soon as possible.
Regards
Please find the solution to the asked query:
Atomic mass is the average of all the isotopes of the element.
But the naturally occurring isotopes of chlorine Cl 35 (75.77%) and Cl 37(24.23%) are relatively present in the ratio 3:1 quite large amount than other elements, hence giving chlorine atomic mass 35.45 approximately 35.5 .
The abundances of the isotopes present in the elements are multiplied by the atomic masses in which they are present.
For example:
We are given the relative abundance of the two isotopes of chlorine. Using these, we can calculate the average atomic mass of chlorine. We will use the following formula
average atomic mass = relative abundance of 37Cl isotope X atomic mass of 37Cl isotope + relative abundance of 35Cl isotope X atomic mass of 35Cl isotope
= (37 X 0.25) + (35 X 0.75)
= 9.25 + 25.25
= 35.5 u
thus the atomic mass of some elements is given in decimals.
Hope this information will clear your doubts regarding the topic. If you have any other doubts please ask here on the forum and our experts will try to solve them as soon as possible.
Regards