Chemical Interactions

        In Quarter 1, I learned Chapter 1，I learned Periodic Table of Elements, each element has atomic mass, and atomic number, like the picture showing. Dmitri Mendeleev was a Russian chemist, he established the first Periodic Table, but elements in the first Periodic Table was founded in columns; in the modern Periodic table, most element are metals, some are nonmetals and metalloids. Atoms are made of  protons, neutrons, and elcctrons; a ion is an atom loses or gains one or more electrons. The Periodic table has distinct regions: Reactive Metals, Transition Metals, Rare Earth Elements, Halogens, Noble Gases, Metalloids and Radioactive Elements.