0
Add your answer:
Earn +20 pts
Is the atomic weight a whole number?
No, it is not.The atomic mass for an isotope of an element is usually close to a whole number but never exactly so. This is because most elements exist in a number of isotopic forms: they are made up of the same number of protons and electrons but differ in the number of neutrons. So the mass of each isotope of the same element will differ from other isotopes by a whole number of mass units. The atomic mass of the element is the average mass of all its isotopes, weighted together in proportion of the abundance of the elements.The worst offender is dysprosium. The element has 66 proton and electrons 162.5.164-Dy has a mass of 163.929 and accounts for 28.3% of the Dy on earth,162-Dy has a mass of 161.927 and accounts for 25.5% of the Dy on earth,163-Dy has a mass of 162.929 and accounts for 24.9% of the Dy on earth,and there are 4 more isotopes accounting for smaller proportions. When averaged, the atomic mass for Dy is 162.5 - as far from a whole number as you can get!
Explain why the atomic mass of an element is usually not given as a whole number even though each individual atom of the element has a whole number of protons and neutrons.?
There are two reasons. The first is that the masses of protons and neutrons are not 1 unit but slightly greater. The mass of an atom is the mass of a whole number of protons, a whole number of neutrons as well as the same number of electrons as protons. Overall, therefore, the mass should be greater than the number of protons and neutrons (electrons have very little mass). But some of the mass is converted to energy which is used to hold the positively charged nucleus together. As a result the mass of carbon-12 is an exact whole number (12) and that is the only element for which that is true. The second, and possibly more important reason is that most atoms are found in the form of isotopes which have different numbers of neutrons and so different masses. The atomic mass listed for an element is an average of the masses of all these isotopes, weighted together according to their abundance of earth.
What is the most important number in this whole world?
your date of birth...without it you are....nothing (no identity!)
Sara says the number with the most digit is always greatest do you agree Explain?
§ In comparing two whole numbers, the one with the most digits is always the greater number. § In decimals the number with the greatest number of digits is not always the greatest.
What does highest frequency mean?
In the context of: In the sequence 1,5,8,4,7,2,6,4,8,4,4,4,6,4,4, What number has the highest frequency? It refers to the meaning of what number is most often So the answer is 4 in this case
What is zinc atomic weight to nearest whole number?
The atomic weight of zinc to the nearest whole number is 65.
How can you determine which isotope of a given atom is the most common?
round the atomic weight to the nearest whole number.
Do all isotopes have whole number atomic masses?
No, not all isotopes have whole number atomic masses. Isotopes are variations of an element with different numbers of neutrons, so their atomic masses can differ slightly from whole numbers due to the weighted average of the masses of the isotopes present in a natural sample.
Are most atoms their mass number is the same as their atomic number?
No. In most atoms the mass number is at least twice the atomic number. A mass number that is the same as the atomic number would indicate a nucleus with no neutrons. Such a nucleus would be highly unstable except in the case of the hydrogen-1 nucleus, which consists of a single proton. In most other stable nuclei there are at least as many neutrons as their are protons. The mass number is the sum of the number of protons and the number of neutrons.
Why are all atomic numbers all whole numbers and most atomic mass number end with a decimals?
Atomic numbers represent the number of protons in an atom, which are whole numbers because protons are discrete particles. Atomic mass numbers, on the other hand, are weighted averages of the isotopes of an element, which can have fractional values due to the presence of isotopes with different masses and abundance.
What is the atomic number of the most electronegative element?
the atomic number for flourine, the most electronegative element, is 9.
The atomic mass and atomic number of berkelium?
The most stable isotope of berkelium - 247Bk - has an atomic mass of 247. The atomic number of berkelium is 97.
What is the number of protons and neutrons in N?
The atomic number of nitrogen is 7. So there are 7 protons and 7 electrons. The number of neutrons depends on the isotope. N-14 has 7 neutrons. N-15 has 8 neutrons. Number of neutrons = Mass number - Atomic number.
What does the 79 mean in the table of elements?
The number 79 in the periodic table refers to the atomic number of the element gold. This number represents the number of protons found in the nucleus of a gold atom.
What is the atomic number for calcium?
The most common calcium isotope, calcium-40, has 20 neutrons.
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.
Why aren't atomic masses of most elements whole numbers?
Atomic masses of elements are not whole numbers because they take into account the weighted average of the isotopes of that element. Isotopes have different mass numbers, and their relative abundance in nature affects the overall atomic mass calculation. This results in most atomic masses being decimal numbers.
