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protons and neutrons
It may seem contradictory that the nucleus of an atom sticks together when we know that like charges repel. Why don't the protons repel each other? It does not seem to fit the predicted pattern.
One theory suggests a model that arranges the protons and neutrons in a series of shells or energy levels like the electrons around the nucleus. The nucleus is held together by mesons, positrons, and neutrinos. Gamma rays are emitted when a proton or neutron drops to a lower energy level. Some nuclei are unstable. They have such a delicate balance of forces holding them together that the slightest disturbance will cause them to fly apart. This results in radioactive decay.
Stable nuclei are determined by the ratio of neutrons to protons. The greater the atomic number, the greater the number of neutrons necessary to keep the nucleus stable. The neutrons tend to act as a buffer among the protons, keeping them from repelling each other with such great force. Figure 9 shows the ratio n:p necessary to ensure a stable isotope.
Notice that as the atomic number increases, the number of neutrons must get larger to offset the increase in nuclear charge. Ratios that deviate very much from the curved line are unstable ratios and indicate radioactive isotopes of that particular element. No completely stable nuclei are in elements 83 and above. All isotopes of elements beyond bismuth (83) are unstable and radioactive.
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∙ 11y ago
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∙ 13y agoIt is equal to the sum of no. of protons and neutrons present in the nucleus.
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∙ 9y agoAtoms mass is equal to sum of protons and neutrons. It does not include electrons.
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∙ 12y agoThe mass number is the sum of protons and neutrons from the atomic nucleus of an isotope.
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∙ 11y agoThe mass number is the sum of protons and neutrons in an atomic nucleus.
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∙ 8y agoprotons and neutrons
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How do you get the mass number by adding neutrons and the atomic number?
mass number = number of protons + number of neutrons The atomic number is equivalent to number of protons.
What is the number of atomic mass?
the mass of an atom of a chemical element expressed in atomic mass units. It is approximately equivalent to the number of protons and neutrons in the atom (the mass number)
Why is the atomic mass of an element not a whole number while the atomic number is?
The atomic number refers to the number of protons in the atom. Since the proton cannot be an in-between number, the atomic number will have to be a whole number. On the other hand, the atomic mass does not have to be a whole number because it is the mass of an atom and is roughly equivalent to the number of protons plus the average number of neutrons in that particular element.
What is indicated by the atomic mass?
the mass of an atom of a chemical element expressed in atomic mass units. It is approximately equivalent to the number of protons and neutrons in the atom (the mass number) or to the average number allowing for the relative abundances of different isotopes.
What comprises the atomic mass?
It is approximately equivalent to the number of protons and neutrons in the atom.
How do you get the mass number by adding neutrons and the atomic number?
mass number = number of protons + number of neutrons The atomic number is equivalent to number of protons.
What is the number of atomic mass?
the mass of an atom of a chemical element expressed in atomic mass units. It is approximately equivalent to the number of protons and neutrons in the atom (the mass number)
What is a mass number atomic mass number?
The atomic number is the number of protons in an atom. This number is fixed and determines what element that atom is. The Atomic Mass is the mass of an atom and is roughly equivalent to the number of protons plus the average number of neutrons that atoms of that particular element.
What is an atomic number and a mass number?
The atomic number is the number of protons in an atom. This number is fixed and determines what element that atom is. The atomic mass is the mass of an atom and is roughly equivalent to the number of protons plus the average number of neutrons that atoms of that particular element.
What is the atomic mass of and atom?
the mass of an atom of a chemical element expressed in atomic mass units. It is approximately equivalent to the number of protons and neutrons in the atom (the mass number) or to the average number allowing for the relative abundances of different isotopes.
Why is the atomic mass of an element not a whole number while the atomic number is?
The atomic number refers to the number of protons in the atom. Since the proton cannot be an in-between number, the atomic number will have to be a whole number. On the other hand, the atomic mass does not have to be a whole number because it is the mass of an atom and is roughly equivalent to the number of protons plus the average number of neutrons in that particular element.
What does atomic mass equal?
the mass of an atom of a chemical element expressed in atomic mass units. It is approximately equivalent to the number of protons and neutrons in the atom (the mass number) or to the average number allowing for the relative abundances of different isotopes.
What does the atomic mass reflects?
the mass of an atom of a chemical element expressed in atomic mass units. It is approximately equivalent to the number of protons and neutrons in the atom (the mass number) or to the average number allowing for the relative abundances of different isotopes.
What is atomic mass of a element?
the mass of an atom of a chemical element expressed in atomic mass units. It is approximately equivalent to the number of protons and neutrons in the atom (the mass number) or to the average number allowing for the relative abundances of different isotopes.
What is the atomic mass comprised of?
the mass of an atom of a chemical element expressed in atomic mass units. It is approximately equivalent to the number of protons and neutrons in the atom (the mass number) or to the average number allowing for the relative abundances of different isotopes.
What is indicated by the atomic mass?
the mass of an atom of a chemical element expressed in atomic mass units. It is approximately equivalent to the number of protons and neutrons in the atom (the mass number) or to the average number allowing for the relative abundances of different isotopes.
What is the definition of 'Atomic Mass'?
the mass of an atom of a chemical element expressed in atomic mass units. It is approximately equivalent to the number of protons and neutrons in the atom (the mass number) or to the average number allowing for the relative abundances of different isotopes.
