What is the reverse formula for finding average atomic mass?

Answer 1

To find the average Atomic Mass of an atom begin by finding the percentage of occurrence for each isotope of the atom and each isotopes mass (amu). Before multiplying, convert percentages to a decimal (move the decimal 2 places to the left) Then multiply each percentage of occurrence by the corresponding mass of that isotope. Do this for all isotopes. Finally, add all these together for the average atomic mass. Ex: Oxygen (3 isotopes) Percent occurrence Isotope Mass

99.759 % 15.99491 amu

.037% 16.99913 amu

.204% 17.99916 amu (.99749)(15.99491) = 15.95632 amu

(.00037)(16.99913) = .0062897 amu

(.00204)(17.99916) = .0367183 amu 15.95632+.0062897+.0367183= 15.99937 15.99937 is the average atomic mass of oxygen!

Answer 2

Atomic weight (symbol: Ar) is a dimensionless physical quantity, the ratio of the average mass of atoms of an element (from a given source) to 1/12 of the mass of an atom of carbon-12 (known as the unified atomic mass unit).The term is usually used, without further qualification, to refer to the standard atomic weights published at regular intervals by the International Union of Pure and Applied Chemistry(IUPAC)]and which are intended to be applicable to normal laboratory materials. These standard atomic weights are reprinted in a wide variety of textbooks, commercial catalogues, wallcharts etc., and in the table below. The fact "relative atomic mass of the element" may also be used to describe this physical quantity, and indeed the continued use of the term "atomic weight" has attracted considerable controversy since at least the 1960s

Answer 3

Well, this is what my chemistry teacher taught me...

AMU=(mass A)(abundant A)+ (mass)(Abundant B)

The "A" represents the first mass and abundant given in the problem. The "B" represents the second.

Hope it helps! =)

Answer 4

The mass number for an atom is the number of protons plus the number of Neutrons as both weigh 1AMU. Technically an electron weighs 0.0005AMU, but most of the time you just leave this out as it is so small.

Answer 5

atomic weight also known as atomic mass. M=m.NA

where:

M=atomic mass NA=avogadro number m=molar mass

Answer 6

somebody answer with the equation written out not in words: ie. x+y=z not x plus y equals z jeez

Answer 7

The atomic mass unit is 1/12 from the atomic mass of an atom of the isotope carbon-12.