Which of the following statements about the elements in the Periodic Table is correct?
- AAn atom of potassium, K, has more protons than an atom of argon, Ar.
- BElements in the same period have similar chemical properties.
- CElements that are non-metals form only covalent bonds with other elements.
- DOn descending Group I from lithium, Li, to caesium, Cs, the metals become less reactive.