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It is mostly because elements have many isotopes and their average comes to be also fractional.We cannot weigh the atom therefore its Atomic Mass is fractional.Even elements with only 1 naturally occurring isotope have fractional mass. This is because the nuclear binding energy is a very large (negative) energy, and it shows up in the atomic mass because of the relativistic adjustment that has to be made --
E= mc2
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Wiki User
∙ 11y ago
Wiki User
∙ 12y ago1. First cause: the atomic weight is the sum of the weights of protons, neutrons ans electrons.; they don't have masses as integers.
2. Second cause: also occurs the so-called mass defect.
Not atomic mass for elements; atomic weight is correct.
Wiki User
∙ 12y agoThat's because all samples of elements have Isotopes ( Isotopes are atoms of the same element with the same atomic number) and atomic mass is calculated as the average of atomic masses of all the Isotopes for each element.
Wiki User
∙ 11y agoElements can exist as different isotopes, atoms with the same proton number but different neutron number. Their atomic masses are therefore an average, based on the number of isotopes, their respective weight and relative abundance.
Wiki User
∙ 11y agoBecause some of the elements masses have the same isotopes inside the atom that is similar to their amount of protons.
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Are the atomic masses of some elements actually fractional?
Atomic mass is not the same as atomic weight. It refers to the weight in amu (atomic mass units ) of a specific isotope. These weights are not whole numbers, the mass of protons and neutrons are slightly different and there is the phenomenon of binding energy of the nucleus which is obseved as a difference in mass (sometimes expressed as the packing fraction). For atomic weights the main reason is that naturally occuring elements consist of mixtures of isotopes.
How atomic number better than atomic mass?
No two elements may have the same atomic number. But two elements may have same atomic mass. Hence atomic number is better than atomic mass.
How were the elements in the periodic table arranged?
By Atomic Mass
What is the atomic mass of this elements?
Gold is a meta element. Atomic Mass of it is 197.
What did Mendeleev think of the properties of the elements depended of?
Atomic Mass.
Why the mass numbers on the periodic table of elements are rarely whole numbers?
Elements also possess isotopes. So their average atomic mass is rarely whole number.
Why are most atomic masses a decimal?
The atomic mass of an isotope of an element is the mass of the nucleons (neutrons + protons) in an atom of that isotope. This is nearly, though not exactly, equal to the number of nucleons, and so is nearly a whole number.The main cause for the atomic mass being fractional is that most elements have numerous isotopes, each with a different number of neutrons and so a different atomic mass. The atomic mass for an element is the average of the atomic masses of all its isotopes, weighted together in the proportion of the isotopes' abundance on earth. It is this weighting together that results in the numbers being fractional.
Are the atomic masses of some elements actually fractional?
Atomic mass is not the same as atomic weight. It refers to the weight in amu (atomic mass units ) of a specific isotope. These weights are not whole numbers, the mass of protons and neutrons are slightly different and there is the phenomenon of binding energy of the nucleus which is obseved as a difference in mass (sometimes expressed as the packing fraction). For atomic weights the main reason is that naturally occuring elements consist of mixtures of isotopes.
Elements were originally placed in order of atomic now they are placed in order of atomic?
Elements were originally placed in order of atomic massnow they are placed in order of atomic number
Is there a difference between mass and atomic mass when dealing with elements?
Generally the term "atomic mass" is used for isotopes. For elements is preferred now "atomic weight".
How atomic number better than atomic mass?
No two elements may have the same atomic number. But two elements may have same atomic mass. Hence atomic number is better than atomic mass.
How were the elements in the periodic table arranged?
By Atomic Mass
How are chemicals related to atomic mass?
The molar mass of a compound is the sum of atomic weights of the contained elements in the molecule.The expression atomic weight is correct for elements; for isotopes is correct atomic mass.
What is the atomic mass of this elements?
Gold is a meta element. Atomic Mass of it is 197.
What did Mendeleev think of the properties of the elements depended of?
Atomic Mass.
Did Mendeleev organize the elements by atomic mass or atomic number?
Mendeleev arranged elements in order of increasing mass. Later modern periodic table was discovered that contains elements arranged by atomic number.
The atomic mass of iodine is less than the atomic mass?
The atomic mass of iodine is less than the atomic mass of all elements with greater atomic number.
