How is each element represented on the periodic table?? A. By it's number of neutrons

B. By it's chemical symbol

C. By it's year of discovery

D. In alphabetical order

This is a characteristic of the elements in the periodic table that shows a pattern. it may increase or decrease across or down the table.

The bond energy for the van der waals bond between two helium atoms is 7.9×10−4ev. assuming that the average kinetic energy of a helium atom is (3/2)kbt, at what temperature is the average kinetic energy equal to the bond energy between two helium atoms

In the following table, all the columns for the element calcium are filled out correctly. element electron structure of atom electron structure of ion net ionic charge calcium 1s22s22p63s23p64s2 1s32s22p63s23p64s1 +1 true false