Download Using the Periodic Table

Atom Anatomy
Target 1.2
Use the Periodic Table to determine:
– Atomic Mass
– Number of Protons
– Number of Neutrons
– Number of Electrons
Using the Periodic Table
• While the periodic table of elements looks
confusing, it is actually very well organized
– There are several patterns (called periodic
trends)
• For example:
– The rows are called periods
– The columns are called families
Using the Periodic Table
• Let’s look at one piece of the table
• The element hydrogen (atomic symbol H)
• While different periodic tables can look
different, they all contain essentially the
same information
Using the Periodic Table
• Let’s look at hydrogen from the periodic
table in your planner
Using the Periodic Table
Using the Periodic Table
• The atomic symbol is a shorthand
abbreviated symbol representing the name
of the atom
– Most of it is based in greek/latin
• That’s why gold is “Au”, lead is Pb, etc.
Using the Periodic Table
• Atomic Number is also the number of
protons in an atom
– You remember protons
• The positively charged particles in the nucleus
• They define the identity of an atom
Using the Periodic Table
• In a neutral atom (one with no electric
charge) the atomic number is also the
number of electrons
– You remember electrons
• The negatively charged particles orbiting the nucleus
Using the Periodic Table
• Atomic Mass
– This represents the total mass of a single atom
of this element
• NOT kg but something called atomic mass units
(amu)
– You round to the nearest WHOLE number
– Equal to the number of protons + the number of
neutrons
• It is often not a whole number
• This is because of isotopes
– That’s another episode…
Using the Periodic Table
• Consider the periodic table entry for carbon
– How many protons? How many electrons?
– What is the mass of a single carbon atom?
– How many neutrons are in an atom of carbon?
Using the Periodic Table
• Atomic Mass = P + N
– number of protons + number of neutrons
– Or just look at the periodic table…
Using the Periodic Table
• Number of Protons = M - N
– Mass - number of neutrons
– Or just look at the periodic table…
Using the Periodic Table
• Number of Neutrons = M - P
– Mass - number of protons
Using the Periodic Table
• Number of electrons
– Assume it is a neutral atom (unless I tell you it’s
not)
– If the atom is neutral, then the number of
positive charges must equal the number of
negative charges
– Electrons = protons
Using the Periodic Table
• Practice!
• How many protons?
• How many electrons?
• Atomic number?
• Atomic mass?
• How many neutrons?
– Mass – protons
– 84 – 36 = 48
More practice
Remember the Learning Target
• Target 1.2
– Use the Periodic Table to determine:
•
•
•
•
Atomic Mass
Number of Protons
Number of Neutrons
Number of Electrons