Download The Periodic Table

THE PERIODIC TABLE
 chemical symbol – is a shorthand way of writing the
name of an element. (like a nickname)
elements are found in the Periodic Table
ex: Fe = Iron
C = Carbon
Ca = Calcium
 Either one capital letter or one capital letter plus one or two
lowercase letters.
- first letter of the elements name
- first letter of the elements name plus another letter from
the name
- some symbols come from the latin name for the element
ex: Silver – Ag (Argentum)
Iron – Fe (Ferrum)
ATOMIC NUMBER…
– is the number of protons in the nucleus of an atom.
Identifies the element. Unique.
- also tell you the number of electrons in a neutral atom.
WHAT INFORMATION IS ON THE PERIODIC
TABLE?
 Atomic Mass
-nucleus contains majority of mass of atom.
-mass of proton is about the same as mass of neutron (1
amu)
-Atomic mass unit (amu)
–used to measure mass of the atom.
-Defined as 1/12 the mass of a carbon atom
 Mass number – sum of the number of protons and neutrons in the
nucleus of an atom
FINDING # NEUTRONS…
 #neutrons = mass number – atomic number
Examples
1. Boron (B)
2. Sodium (Na)
atomic #
atomic #
mass #
mass #
p+
p+
e-
e-
n0
n0
ISOTOPES
…are atoms of the same element that have different numbers of
neutrons.


can have different properties
because most elements have more than one isotope, each
element is given an average atomic mass- this is the number on
the periodic table
 Ex 1: Carbon – 12 and Carbon - 14