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.

Many reactions take place in aqueous solution. when potential reactants are mixed, a reaction will occur if there is some driving force that favors the formation of products. it is often convenient to categorize reactions in terms of these driving forces: precipitate formation, in which an insoluble solid is formed, weak electrolyte formation, as in a neutralization reaction involving water, or transfer of electrons, as in a redox reaction. these reactions can be represented by full molecular equations, which contain all species in the reaction mixture, or by net ionic equations, which show only the species that actually undergo a change. the latter does not contain the spectator ions, which do not undergo a net change or do not take part in the reaction. part a when the following two solutions are mixed: k2co3(aq)+fe(no3)3(aq) the mixture contains the ions listed below. sort these species into spectator ions and ions that react. drag the appropriate items to their respective bins. view available hint(s) spectator ions ions that react part b what is the correct net ionic equation, including all coefficients, charges, and phases, for the following set of reactants? assume that the contribution of protons from h2so4 is near 100 %.ba(oh)2(aq)+h2so4(aq)→ express your answer as a chemical equation. view available hint(s) nothing provide feedback

This classification of drug typically changes the brain's chemistry and reduces its ability to create its own endorphins.

Which buffer would be better able to hold a steady ph on the addition of strong acid, buffer 1 or buffer 2? explain. buffer 1: a solution containing 0.10 m nh4cl and 1 m nh3. buffer 2: a solution containing 1 m nh4cl and 0.10 m nh3