Periodic Table

Periods, groups, and blocks

• useful for quickly determining an atom’s electron configuration

Period

• row in the periodic table
  • each element in a period has the same number of shells

Group

• column in the periodic table
  • each element has the same number of valence electrons

Block

• set of related elements
  • each element has its valence electrons in the same orbital

d-block

• “transition” elements
• electrons are never added to the valence shell
  • period - 1 = subshell that electrons are placed in

f-block

• “inner transition” elements
• similar to d-block, electrons are not added to the valence shell
  • period - 2 = subshell that electrons are place in

Links

• https://ptable.com — good online periodic table