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How do you calculate the average atomic mass when given percent abundance and mass number?
Wiki User
∙ 15y ago
start by getting its isotpic mass. you can do this by taking the mass of an atom and dividing it by 12.01, which is kinown as the carbon standard and is used in the calculation for any element. this will give you a ratio. multiply this number by 12 amu and it will give you the isotopic mass. Next, multiply this number by the percentage in abundance as a fraction (ex. 92.12% = .09212)..... the resulting number will be your Atomic Mass ONLY for that isotope. To calculate the ATOMIC MASS of an element, you must repeat the previous steps for ALL isotopes. When this is finished, add the atomic masses for the isotopes together the get the atomic mass for that element. For a visual, we'll use Si (28)
(mass of Si atom)/ (mass of C standard) = 2.331411 that's your ratio
2.331411 x 12 amu = 27.97693 amu .... that's your isotopic mass for that specific isotope
27.97693 x .9223 (or 92.23%) = 25.8031..... that's your atomic mass for that isotope
Now the similar calculations done with the other isotopes of silicon give us..
Si(29) as (28.976495x.0467=1.3532) and Si(30) as (29.973770x.0310=.9292)
Lastly, add those together to get...
25.8031 + 1.3532+ .9292 = 28.09 amu which is the atomic mass for the element Silicon.
Good luck, chemistry sucks.
Wiki User
∙ 14y ago
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How is the atomic mass of each element on the periodic table calculate?
The atomic mass listed on most periodic tables is actually the average atomic mass representing the average atomic masses of the various isotopes of an element depending on their percent natural abundance. Refer to the answers.com question: What is the formula for finding average atomic mass? for a detailed explanation on how to calculate this value. (What_is_the_formula_for_finding_average_atomic_mass)
Why do elements which exists as isotopes have fractional atomic mass?
Each isotope of an element has a different Atomic Mass, so an average is taken of all the isotopes, but the average is weighted because the natural abundance (%) of each isotope is factored in. If hydrogen-1 is much more abundant than deuterium and tritium, then the weighted average will be closer to 1 than 2 or 3 but not a whole number. The following equation shows how percent abundance factors into the weighted average. (atomic mass A)(X% abundance) + (atomic mass B)(Y% abundance)...=(weighted average of all isotopes of the element)(100% abundance)
How do you calculate the atomic mass of an element with different isotopes?
To calculate average atomic mass from different isotopes of an element, we take into account the relative atomic masses of isotopes and their relative abundance on Earth. The following formula is used to calculate the needful : atomic mass = mass of isotope x percent abundance + mass of isotope x percent abundance / 100 (whole expression divided by 100)
What is the average atomic mass of an element with two isotopes of 220 and 250?
To calculate the median atomic weight, the relative abundance of each isotope could be calculated or given.
Calculate the average atomic mass of copper-63 and copper-65?
63.6166 Relative abundance of Copper-63 is 69.17% and Copper-65 is 30.83%
What is percent abundance?
Take percent abundance times atomic mass for each isotope then add all up for average atomic mass.
How is the atomic mass of each element on the periodic table calculate?
The atomic mass listed on most periodic tables is actually the average atomic mass representing the average atomic masses of the various isotopes of an element depending on their percent natural abundance. Refer to the answers.com question: What is the formula for finding average atomic mass? for a detailed explanation on how to calculate this value. (What_is_the_formula_for_finding_average_atomic_mass)
Why do elements which exists as isotopes have fractional atomic mass?
Each isotope of an element has a different Atomic Mass, so an average is taken of all the isotopes, but the average is weighted because the natural abundance (%) of each isotope is factored in. If hydrogen-1 is much more abundant than deuterium and tritium, then the weighted average will be closer to 1 than 2 or 3 but not a whole number. The following equation shows how percent abundance factors into the weighted average. (atomic mass A)(X% abundance) + (atomic mass B)(Y% abundance)...=(weighted average of all isotopes of the element)(100% abundance)
How do you calculate the atomic mass of an element with different isotopes?
To calculate average atomic mass from different isotopes of an element, we take into account the relative atomic masses of isotopes and their relative abundance on Earth. The following formula is used to calculate the needful : atomic mass = mass of isotope x percent abundance + mass of isotope x percent abundance / 100 (whole expression divided by 100)
What is the average atomic mass of an element with two isotopes of 220 and 250?
To calculate the median atomic weight, the relative abundance of each isotope could be calculated or given.
What is the automic mass of chlorine atom?
Chlorine 35: exact weight: 34.968852, percent abundance: 75.77 Chlorine 37: exact weight: 36.965903, percent abundance: 24.23 average atomic weight; 35.453
How percentage abundance is related to atomic number?
Percent abundance is not related to atomic number. Atomic number is the number of protons in the atomic nuclei of an element, and is unique to each element.
Calculate the average atomic mass of copper-63 and copper-65?
63.6166 Relative abundance of Copper-63 is 69.17% and Copper-65 is 30.83%
How do you calculate the average atomic mass of a element?
The mass of the isotope multiplied by its relative abundance plus the the mass times abundance of other isotopes.(mass of isotope)(relative abundance) + (mass of isotope)(relative abundance) = average atomic massExample: Carbon can be naturally found as carbon- 12 or carbon- 13. The mass of carbon- 12 is 12 amu and it makes up 98.93% of naturally found carbon. The mass of carbon- 13 is 13.00335 amu, and it makes up 1.07% of naturally found carbon. So the equation to calculate the average atomic mass of carbon is:(0.9893)(12 amu) + (0.0107)(13.00335 amu) = 12.01 amu
The average atomic mass of an element is the average of the atomic masses of its?
The average atomic mass of an element is the average of the atomic masses of its isotopes (that is a weighted average). You have to take into account the abundance of each isotope when they do your averaging.
How do you calculate percent abundance for antimony?
The atomic mass of an element is the weighted average of the masses of its isotopes. You know that: Antimony-121 has a mass of 120.9038 u, x% abundance Antimony-123 has a mass of 122.9042 u, y% abundance There are only 2 isotopes for antimony and their percent abundances should add up to 100%. In other words: x% + y% = 100% y = 1-x (percentages written as decimals) So, now let's put everything together. In order to calculate the atomic mass, multiply the percent abundance of an isotope by its atomic mass; then add the product of all the isotopes: (Atomic Mass of Antimony-121)(Percent Abundance of Antimony-121) + (Atomic Mass of Antimony-123)(Percent Abundance of Antimony-123) = Atomic Mass of Element Antimony (120.9038 amu)(x) + (122.9042 amu)(y) = 121.760 amu Replacing 1-x for y gives: (120.9038 amu)(x) + (122.9042 amu)(1-x) = 121.760 amu Solve for x: 120.9038x + 122.9042 -122.9042x = 121.760 amu -2.0040x = -1.1442 x = 0.57096 = 57.096% Solve for y: y = 1 - x y = 1 - 0.57096 = 0.42904 = 42.904%
Chlorine has 2 isotopes and These have atomic masses 34.9689 amu and 36.9659 amu respectively Their ratio in nature is 75.77 percent and 24.23 percent respectively Calculate the average atomic ma?
Atomic mass of = 34.9689 amu Atomic mass of = 36.9659 amu % of = 75.77 % of = 24.23 Average atomic mass = amu Found this answer on examville.com
