Lesson 4.2: The Periodic Table
- The periodic table contains information about the different elements that make up all the solids, liquids, and gases in the known universe.
- Even though there are only about 100 elements, the atoms of these elements make up the millions of substances in all matter.
Periodic Table of the First 20 Elements
- This is a close-up of the first 20 elements from the periodic table.
- Many common substances are composed of atoms from these first 20 elements.