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.