Consider an element Z that has two naturally occuring isotopes with the following percent abundances: the isotope with a mass number 22.0 is 65.0% abundant; the isotope with a mass number 24.0 is 35.0% abundant. What is the average atomic mass for element Z? Round your answer to the hundredth.

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Chemistry worksheet - i am not sure what they are asking for exactly?

Answer asap need by wednesday morning explain how a buffer works, using an ethanoic acid/sodium ethanoate system including how the system resists changes in ph upon addition of a small amount of base and upon addition of a small amount of acid respectively. include the following calculations in your i. calculate the ph of a solution made by mixing 25cm3 0.1m ch3cooh and 40cm3 0.1m ch3coo-na+. [ka = 1.74 x 10-5 m] ii. calculate the ph following the addition of a 10cm3 portion of 0.08 m naoh to 500cm3 of this buffer solution. iii. calculate the ph following the addition of a 10cm3 portion of 0.08 m hcl to 200cm3 of the original buffer solution.