Periodic Table

The Periodic Table

.

all atoms want a full outer cloud!

Moseley arranged table again by atomic number (what we use today)

PERIODIC

meaning of

repeating or followinga regular pattern

:

3

classes

l

l

nonmetals

metalloids

metals

groups - vertical columns of the table

symbol

element name

atomic mass

atomic number

periods - horizontal rows of the table

KEY DEFINITIONS

created by Mendeleev (by atomic mass)

valance electrons- electrons in the most outer cloud

groups 1 & 2:reactive metals

group 1: alkali metals-1 valance-reactive-low densitygroup 2: alkaline-earth metals-reactive, less than group 1-2 valance-silver, less dense tan group 1

groups 3-12:transition metals

-all metals-2 valance-less reactive than first 2groups-shiny, good conductors-high densities & melting points

group 13: boron group-3 valance-reactivegroup 14: carbon group-4 valance-reactivity variesgroup 15: nitrogen group-5 valance-reactivity variesgroup 16: oxygen group-6 valance-reactive

groups 13-16:metalloids

group 17: halogens-7 valance-very reactive-when reacting, form saltsgroup 18: noble gases-8 valance-not reactive

groups 17 & 18:nonmetals

Ashley TangPeriod 1