Periodic Table

Periodic Table

1. Elements and atoms

   • Element
     • An element is a substance made from only one type of atom.
   • Atom
     • An atom is the smallest piece of an element that can exist.

2. Atomic number

   • Every element has a unique atomic number (also known as the proton number). This is the number of protons in the nucleus of each atom.

3. Groups in the periodic table

4. Electron arrangement

   • Electrons in period 1
   • Electrons in period 2
   • Electrons in period 3

5. Trends in the periodic table

   • Down the group
     • the number of outer shell electrons is the same
     • the number of complete electron shells increases by one.
   • Across the group
     • the number of outer shell electrons increases by one
     • the number of complete electron shells stays the same.

Images and files in the map