Question

The numbers on the top of the coumns on the periodic table represent

A The number of valence electrons that each of those elements in that column have.

B The number of core electrons that each of those elements in that column have.

C The number of orbital levels that each of those elements in that column have.

D None of the above

A?

Answer 1

Since there are several numbers at the top and different people use different methods in interpreting the periodic table, I don't know how to interpret the question. I think A is correct for representative elements; i.e., those in group IA, IIA, IIIA.....VIIA but for many of the transition elements A is not true. For example, Pd is [Kr]4d10 but 10 is not the usual valence of Pde. Mo is another problem, etc. I think I would be inclined to choose D.