Editing Periodic table (section)

== Classification of Elements ==

=== Major Categories ===

# '''Metals''' (≈75% of elements)
#* Generally good conductors of heat and electricity
#* Typically malleable and ductile
#* Usually form positive ions
#* Located on the left and center of the table
# '''Nonmetals'''
#* Poor conductors
#* Typically brittle as solids
#* Often form negative ions
#* Located on the right side of the table
# '''Metalloids'''
#* Exhibit properties intermediate between metals and nonmetals
#* Include elements such as silicon, germanium, and arsenic
#* Form a diagonal border between metals and nonmetals

=== Blocks ===

# '''s-block'''
#* Groups 1 and 2
#* Includes alkali metals and alkaline earth metals
#* Characterized by s-orbital filling
# '''p-block'''
#* Groups 13-18
#* Includes many nonmetals and metalloids
#* Shows diverse chemical behaviors
# '''d-block'''
#* Groups 3-12
#* Contains transition metals
#* Exhibits variable oxidation states
# '''f-block'''
#* Lanthanides and actinides
#* Shows similar chemical properties within each series
#* Complex electronic structures