Studied by 31 people
valence electrons
located on outermost electron shell
octet rule
eight electrons in outermost electron shell (valence electrons)
periodic law
elements show regular and repeating properties when arranged by increasing atomic number
periodic table of elements
table arranged by atomic number and number of valence electrons
period
a row on periodic table
group
arranged by same number of valence electrons
1, 2, 13-18
what are the main group elements?
metals
hard, dense, shiny solids
nonmetals
poor conductors of electricity; gasses and liquids
semimetals
solids with characteristics between nonmetals and metals
alkali metals
group one; very soft, shiny metals
alkali earth metals
group two; harder, denser and less reactive
transition metals
groups 3-12; strength and durability
inner transition metals
between groups 3 and 4 (under table); radioactive
13-16
what are the mixed groups?
carbon
found in graphite and diamond
halogens
group 17; “salt formers”
noble gasses
group 18; found in their pure states in nature
