On a mission to a newly discovered planet, an astronaut finds copper abundances of 69.15 % for 63Cu and 30.85 % for 65Cu. What is the atomic mass of copper for this location? The mass of 63Cu is 62.9300 amu . The mass of 65Cu is 64.9200 amu .

Express your answer to two decimal places, and include the appropriate units.
what are value and unit?

Also,
The astronaut then measures the abundance of silicon on the new planet, obtaining the following results:
Isotope Abundance
(%) Mass
(amu)
28Si 73.71 27.98
29Si
14.93 28.98
30Si 11.36 29.97
What is the atomic mass of silicon for this planet?
Express your answer to two decimal places, and include the appropriate units.

b.

the accuracy of the data.

c) should be the answer.

explanation:

two years ago, when picking flowers in the mountains back of yosemite valley, i found a book. it was blotted and storm-beaten; all of its outer pages were mealy and crumbly. the paper seemed to dissolve like the snow beneath which it had been buried, however; many of the inner pages were well preserved. and although all were more or less stained and torn, whole chapters were easily readable. this is the condition of the great open book of yosemite glaciers today; its granite pages have been torn and blurred by the same storms that wasted the castaway book.

two years ago, when picking flowers in the mountains back of yosemite valley; i found a book. it was blotted and storm-beaten, all of its outer pages were mealy and crumbly. the paper seemed to dissolve like the snow beneath which it had been buried, however, many of the inner pages were well preserved. and although all were more or less stained and torn; whole chapters were easily readable. this is the condition of the great open book of yosemite glaciers today, its granite pages have been torn and blurred by the same storms that wasted the castaway book.