Chemistry, asked by nitingarg3218, 1 year ago

Why are the atomic weights of the elements generally not integers? cite two reasons?

Answers

Answered by Aayush00
5
They show the average atomic mass of all isotopes

Explanation:

like with chlorine, some has a mass of 35, others have a mass of 37.
3/4 of the chlorine is 35 the rest is 37.
This means that most of the chlorine atoms are 35 so the average atomic mass is 35.5.
If the abundance is 50:50 the average atomic mass would be 36.

NATURE IS SOOO RANDOM, And doesnt allow such a thing to happen! 

Answered by genghiskhan329
1

Answer:

because of loss of some portion of mass in binding of nuclei and also mass of one proton and neutron is not exactly equal to 1 amu.

Explanation:

If you are talking about the average of atomic masses of isotopes then someone has already answered that. But even if we consider a single isotope of an element it's mass isn't integer. One reason is when neutrons and protons combine to form a nuclei they loss some fraction of their mass in the form of energy known as binding energy. E-g if you have 8 protons and 7 neutrons and you add them it will give 15. From there you get 15 amu. But it was found experimentally that the mass when these protons and neutrons combined was a little bit less than 15. Other reason for not having integers in atomic weight is the fact that the mass of neutron and proton are 1.00893 amu, 1.00813 amu respectively. So its obvious if you add them you end up getting numbers that are not integers but decimal.

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