Which notations represent atoms that have the same number of protons but a different number of neutrons?

The most efficient way to establish the best possible economizer position is to measure

Amixture with the same composition throughout is!

Amixture initially contains a, b, and c in the following concentrations: [a] = 0.300 m , [b] = 1.05 m , and [c] = 0.550 m . the following reaction occurs and equilibrium is established: a+2b⇌c at equilibrium, [a] = 0.140 m and [c] = 0.710 m . calculate the value of the equilibrium constant, kc.