Periods are
horizontal rows(1-7)
groups are
vertical columns (1A-8A)
Metals are
70%, shiny, ductile, heat, electricity
Non-metals are
dull, brittle, good insulators
metalloids are
better conductors than non-metals, not as good as metals
3B-12B is
transition metals
1A-8A is
representative elements
Alternative System
1-18
1A
alkali metals
2A
Alkaline Earth Metals
3A-6A
no common names
7A
Halogens -1
8A
Noble Gases
P+
, proton: positively charged +1
n
neutron, charge is 0
e-
electron,
An atom consist of
a nucleus that contains protons and neutrons
-electrons in a large empty space between nucleus
Atomic # is also
Protons and Electrons
isotopes
atoms of the same element, but have different atomic mass
nucleus that is radioactive
radiation
Atom
smallest particle of an element that retains characteristics of that element
representative elements
1A-8A
Valence Electrons
# of electrons in the outermost energy level
Group # gives the
# of valence electrons for the representative elements
Atomic size increases going
down a group
atomic size decreases
going up from left to right across a period
metallic characters
the ability to lose electrons
-more prevalent in metals
-less for nonmetals on the right side of the periodic table, which doesn't lose electrons easily