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The mass of an electron is very, very small compared to the mass of a proton and a neutron. The mass of the proton and the neutron are almost exactly the same. Thus, the mass of an entire atom is essential just the mass of the proton plus the mass of the neutron.

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Q: Why does the atomic mass only add protons and neutrons?
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Do protons and nuetrons have same atomic number?

no. -------------- In atoms, only the Protons count as atomic number The neutrons and the protons together is as the atomic mass


What does Atomic mass tell you?

The Atomic Mass tells you how many Protons and Neutrons are in the atom. It is approximately the sum of the number of protons and neutrons found in the nucleus of an atom. Basically the weight of the neutrons and protons in one atom


Does atomic number equal atomic mass?

No. Atomic mass is the atomic number plus the number of neutrons. The only exception to this is the most common isotope of hydrogen, which has 1 proton and no neutrons, thus both the atomic mass and number are 1.


The atomic weight of an element whose atoms contain 8 protons 8 electrons and 8 neutrons is?

That would be an oxygen isotope and it's Atomic Mass would be 16. (Protons + Neutrons) The mass of an electron is so minuscule that it is not even factored into the mass.


What equals atomic mass minus protons?

Roughly, the number of neutrons. Note that the atomic mass is only approximately equal to the number of protons plus the number of neutrons - there is a relatively small discrepancy, due to the binding energy.


Can you identify an atom without knowing number of neutrons in it?

Yes, and in order to find the Number of Neutrons, subtract Atomic Mass from Number Of Protons, the result will be the Number of Neutrons for that atom *No. Of Neutron=Atomic Mass - Number Of Protons


The atomic mass of an element whose atoms consist of eight protons nine neutrons and eight electrons is what?

To calculate atomic mass, only the amount of protons and neutrons will be summed. So eight protons plus nine electrons equals seventeen atomic mass units.


How are atomic number and atomic mass related to atomic structure?

The atomic number tells how many protons are in the atom, and the atomic mass tells how many neutrons and protons are in the atom together. Like Oxygen has an atomic number of 8. It also has 8 protons. It's atomic mass is 16. It also has 16 neutrons and protons. Helium's atomic number is 1. It only has 1 proton. It's atomic mass is 1 because it doesn't have any neutrons.


What is the difference between the mass number and the atomic number of an element?

The difference between the atomic number and the mass number is that the atomic number is the number of protons in the nucleus of an atom of that element. The mass number is the total number of protons and neutrons in the atom.Atomic number = number of protonsMass number = total number of protons + neutrons


What is atomic mass A and neutron number N for given atom?

Atomic mass is the number of protons and neutrons that make up an atom. The neutron number is only the number of neutrons present in the atom. This can be found by subtracting the number of protons from the atomic mass.


Why do protons and electrons aproximately equal a atomic mass?

Protons are much heavier (1800 X approx) than electrons! Atomic mass is due to the mass of the protons and neutrons only a very small % of atomic mass is due to electrons.


Why is lithium's mass number a decimal number?

The mass number is a whole number, but the atomic mass may not be. Mass numbers are the total number of neutrons and protons in an isotope (different from atomic numbers, which are the whole numbers of protons only). These are also whole numbers, and for most lithium, it is 7. The mass number is 6 for lithium-6, which has only 3 neutrons. However, the "atomic mass" of an element is measured in atomic mass units, which are 1/12 of the weight of a carbon-12 atom (6 protons and 6 neutrons). Since neutrons are slightly heavier than protons, and there are more neutrons than protons in lithium-7 (3 protons to 4 neutrons), the atomic mass is slightly more than 7.