Percent (%) Composition of CuO
Cu = 1 x 50g - Multiply by one as there is one Cu
O = 1 x 12.5g - Multiply by one as there is one O
CuO = 62.5g
% for Cu = 50g over 62.5 multiplied by 100 = 80%
% for O = 12.5g over 62.5 multiplied by 100 = 20%
Final Answer :
<em>Percent (%) Composition of CuO = </em>80% (Cu) & 20% (O)
Answer : The moles of
formed are, 22.3 moles.
Explanation : Given,
Moles of
= 16.72 mol
The given chemical reaction is:

From the balanced chemical reaction, we conclude that:
As, 3 moles of
react to give 4 moles of 
So, 16.72 moles of
react to give
moles of 
Therefore, the moles of
formed are, 22.3 moles.
Longer than visable light
Educated Guess Here!
Since Br-80 does not exist, maybe that means Br-79 or Br-81 have very unequal abundances. For example, Br-79 may have 75% abundance whereas Br-81 may have 25% abundance.
Combination or synthesis reaction