Why do most mass numbers on the periodic table have a decimal?

The conventional equilibrium constant expression (kc) for the system below is: 2icl(s) ⇄ i2(s) + cl2(g) [cl2] ([i2] + [cl2])/2[icl] [i2][cl2]/[icl]2 none of the listed answers are correct [i2][cl2]/2[icl]

Asample of ammonia reacts with oxygen as shown. 4nh3(g) + 5o2(g) 4no(g) + 6h2o(g) what is the limiting reactant if 4.0 g of nh3 react with 8.0 g of oxygen? o2 because it produces only 0.20 mol of no. nh3 because it produces only 0.20 mol of no. o2 because it produces two times less no than nh3. nh3 because it produces three times more no than o2.

Ted and emily played a mixed doubles tennis match against jack and brenda. in the second match. ted and brenda played against jack and emily. which type of chemical reaction does the situation demonstrate?