Answer:
A lot
Step-by-step explanation:
- As you go down a group, the elements get larger in size
- All of the elements of the same group have the same # of valence electrons
- As you go to the right of a period, the # of electrons in the outermost shell increases
- The elements at the top right of the table have the highest electronegativity
- Groups 13 through 17 are nonmetals
- The last group contains noble gases
etc.