The Periodic Table
• The Periodic Table gives us SO much information
about the world around us, but first you have to
know how to read it!
Each of these
little squares
tells us about
one specific
element.
An Element
• Where an element is on
the table can give you a
lot of information about
it.
• We are going to look at
what information you
can find out from each
element’s square on the
Periodic Table.
5
B
Boron
10.811 amu
This is what the
square for Boron looks
like.
An Element
• Find Boron on your
periodic table.
• A basic periodic table will
give you these four pieces
of information about
each element. We will go
over each one and what
they mean.
5
B
Boron
10.811 amu
Atomic Number
• This is the Atomic Number
for Boron.
• The atomic number tells you
how many protons and
electrons an atom of Boron
has. (So Boron has 5 protons and 5 electrons).
• The elements are also arranged
on the Periodic Table so that
the atomic numbers go in
order.
5
Chemical Symbol
• This is the Chemical Symbol
for Boron.
• The chemical symbol is the
same no matter what language
you read the table in.
• Every element has a unique
chemical symbol.
• The first letter is always
capitalized. If there is a second
letter, it is always lowercase.
B
Chemical Name
• This is the Chemical Name.
• The chemical name may be
different for a scientist
viewing the table in a
different language.
Boron
Atomic Mass
• This is the Atomic Mass
of Boron.
• Atomic mass is
measured in Atomic
Mass Units (amu’s).
• It is the sum of the mass
of all of the protons,
neutrons, and electrons
in one atom of Boron.
10.811 amu
Atomic Mass (continued)
• Electrons have very little
mass. So little that they
barely register in the
atomic mass.
• For this reason, the
atomic mass really only
measures the mass of the
protons + the neutrons.
10.811 amu
Atomic Mass (continued)
• Protons and Neutrons
each weigh about 1 amu.
• Because they weight 1
amu and we know how
many protons each
atom has – it is easy to
figure out how many
neutrons each atom has.
10.811 amu
Neutrons
To find the number of
neutrons:
1st – Round off the atomic mass to the
nearest whole number
• 10.811 rounds to 11
2nd – Subtract the number of protons (the
atomic number) from your new atomic
mass
• 11 – 5 = 6
The answer is the number of
neutrons the atom has!
5
B
Boron
10.811 amu
Neutron Practice
Let’s practice on a new element!
•
What is the atomic number for Fluorine?
•
What is the atomic mass of Fluorine?
•
What would you round the atomic mass
too?
•
__________ - ___________ = _________
(rounded atomic mass )
•
(atomic number)
(neutrons)
9
F
Fluorine
How many neutrons does Fluorine have?
18.998404 amu