I want to thank your team (Jeff) for finding a new writer when you were unable to reach my existing writer to revise my paper. I appreciate your professionalism and efforts. Thanks
Report (any type)/Brief report
22/09/2021
The term “” refers to the mass of a single atom. The mass of a single atom of carbon-12 is defined as exactly 12 u.
The term atomic mass is also often used (though technically, incorrectly) to refer to the average atomic mass of all of the of an element.
This second definition is actually the relative atomic mass of an element — a single average value of the element’s mass based on the masses of its isotopes.
Carbon has 15 known isotopes, of which only two (##””^12″C”color(white)(l) “and”color(white)(l) “”^13″C”##) are stable. ##””^14″C”## exists only in trace amounts, so it makes no measurable contribution to the average atomic mass.
Carbon consists of 98.93% ##””^12″C”## (12 u) and 1.07% ##””^13″C”## (13.003 u). What is the average atomic mass of these isotopes?
METHOD 1
To find the average atomic mass, you take a certain number of atoms, find the total mass of each isotope, and then divide the total mass of all the atoms by the total number of atoms.
Assume that you have, say, 10 000 atoms of carbon. Then you have 9893 atoms of ##””^12″C”## and 107 atoms of ##””^13″C”##.
##”Mass of”color(white)(l) “”^12″C” = 9893 color(red)(cancel(color(black)(“atoms”))) × “12 u”/(1 color(red)(cancel(color(black)(“atom”)))) = “118 716 u”##
##”Mass of”color(white)(l) “”^13″C” = 107color(red)(cancel(color(black)(“atoms”))) × “13.003 u”/
(1 color(red)(cancel(color(black)(“atom”)))) =color(white)(ml) “1 390 u”##
##”Total mass”color(white)(l)color(white)(mmmmmmmmmmmmm) = “120 110 u”##
##”Average mass” = “120 110 u”https://studydaddy.com/”10 000 atoms” = “12.011 u”##
METHOD 2
Another way of determining the average mass is to multiply the atomic mass of each isotope by its percentage and then add the numbers.
The two methods are mathematically equivalent. Thus,
##”Average mass” = “(0.9893 × 12 + 0.0107 × 13.003) u” = “(11.872 + 0.139) u” = “12.011 u”##
Method 2 is probably mathematically simpler, but Method 1 makes it clear that you are determining an average mass.
Choose the method that you prefer.
I want to thank your team (Jeff) for finding a new writer when you were unable to reach my existing writer to revise my paper. I appreciate your professionalism and efforts. Thanks
Delivering a high-quality product at a reasonable price is not enough anymore.
That’s why we have developed 5 beneficial guarantees that will make your experience with our service enjoyable, easy, and safe.
You have to be 100% sure of the quality of your product to give a money-back guarantee. This describes us perfectly. Make sure that this guarantee is totally transparent.
Read moreEach paper is composed from scratch, according to your instructions. It is then checked by our plagiarism-detection software. There is no gap where plagiarism could squeeze in.
Read moreThanks to our free revisions, there is no way for you to be unsatisfied. We will work on your paper until you are completely happy with the result.
Read moreYour email is safe, as we store it according to international data protection rules. Your bank details are secure, as we use only reliable payment systems.
Read moreBy sending us your money, you buy the service we provide. Check out our terms and conditions if you prefer business talks to be laid out in official language.
Read more