Answer 1: Matter is made up of atoms and molecules.
Answer 2: Dmitri Mendeleev is called the father of the periodic table.
Answer 3: Mendeleev organized his periodic table by arranging the elements in order of increasing atomic mass.
Answer 4: The similar chemical properties found in groups on the table are caused by the elements having the same number of valence electrons.
Answer 5: Metals are located on the left side of the periodic table, while nonmetals are located on the right side.