Calculate the average atomic mass for the element beryllium, given this information about the relative abundance of its 3 isotopes.
Be-8 = 0.2% Be-9 = 98.9% Be-10 = 0.9%. Please show all your work.

Less Credit so, I won't able

 9.007

Explanation:

Be-8  8 x   0.20%  =0.016

Be-99 x98.90%=     8.901

Be-1010 x0.90%  =        0.09

        100.00%       9.007

consider the reaction below.

 no rx

at 500 k, the reaction is at equilibrium with the following concentrations.

[pci5]= 0.0095 m

[pci3] = 0.020

[ci2] = 0.020 m

what is the equilibrium constant for the given reaction?

0.042

0.42

2.4

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