 P.T. displays the symbols and names of the elements, along with information about the structure of their atoms  The different colors of squares differentiates the groups of elements ◦ Group 1A -> alkali metals ◦ Group 2A –> alkaline earth metals ◦ Group 7A-> halogens

 Electron Configuration in Groups ◦ Elements can be sorted into noble gases, representative elements, transition metals, or inner transition metals based on their electron configuration  Noble Gases  Group 8A  Rarely take part in reactions  All end with an s & p orbital

 Representative Elements  Display a wide range of physical and chemical properties  Some are metals, nonmetals, or metalloids  s & p orbitals are not filled completely Compare the 2 below: which is a noble gas and which is a representative element? 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 1s 2 2s 2 2p 6 3s 2 3p 4

 Transition Elements ◦ Group B ◦ 2 types  Transition metal  Highest occupied s sublevel and a nearby d sublevel contains electrons  Characterized by having the d orbital  Inner transition metal  Highest occupied s sublevel and nearby f sublevel generally contain electrons  Characterized by f orbitals that contain electrons

◦ Blocks of Elements  P.T. can be divided into different blocks  Orange= s orbital  Green= d orbital  Purple= p orbital  Blue= f orbital