The periodic table is organized by a) atomic mass. b) atomic size. c) atomic number. d) atomic periodicity.

The correct option is: c) atomic number

Explanation:

The periodic table is a table in which all the chemical elements are organized in the increasing order of atomic number (Z), which is unique for each chemical element.

The atomic number of a neutral element is equal to the number of protons present in the nucleus of the atom and the number of electrons in the atom.

each  column  of the  table  is called a group. elements in a group share similar properties. groups are  read  from  top  to  bottom. metal. metalloid. nonmetal. solid. liquid. gas. fe. hg. o.  2. 3. 4. 5. 6. 7. 8. 9.  2. beryllium. 9.012. 4.  sodium. 22.990.  11. 3.  magnesium. 24.305.  12.  potassium. 39.098.  19. 4.  calcium. 40.078.  20. i guess  i