Catalyst

Objective SWBAT explain how the periodic table is set up. SWBAT identify & calculate atomic number. SWBAT identify & calculate atomic mass / mass number.

Periodic Table Set Up 10.23.2008

Elements Elements have a characteristic (unique) set of chemical & physical properties. First organized into “periodic table” by Russian Chemist Mendeleev

Periodic Table Set Up 10.23.2008 Elements Have unique chem. & physical properties Organized into periodic table

Elements There is a universally understood symbol for each element. An element is represented in one of 2 ways: 1. A capital letter Boron: Sulfur: Potassium:

Elements There is a universally understood symbol for each element. An element is represented in one of 2 ways: 1. A capital letter Boron: B Sulfur: S Potassium: K (from the Latin: Kalium)

Periodic Table Set Up 10.23.2008 Elements Symbols Have unique chem. & physical properties Organized into periodic table 2 ways to represent element: 1. Capital letter (e.g. B = Boron, S = Sulfur, Potassium = K)

Elements There is a universally understood symbol for each element. An element is represented in one of 2 ways: 2. A capital letter + lowercase letter Calcium: Magnesium: Silicon:

Elements There is a universally understood symbol for each element. An element is represented in one of 2 ways: 2. A capital letter + lowercase letter Calcium: Ca Magnesium: Mg Silicon: Si

Periodic Table Set Up 10.23.2008 Elements Symbols Have unique chem. & physical properties Organized into periodic table 2 ways to represent element: 1. Capital letter (e.g. B = Boron, S = Sulfur, Potassium = K) 2. Capital letter + lowercase letter (e.g. Ca = Calcium, Mg = Magnesium, Si = Silicon)

Reading Periodic Table Atomic # Symbol Name Atomic Mass / Mass #

Periodic Table Set Up 10.23.2008 Symbols Reading Periodic Table - 2 ways to represent element: 1. Capital letter (e.g. B = Boron, S = Sulfur, Potassium = K) 2. Capital letter + lowercase letter (e.g. Ca = Calcium, Mg = Magnesium, Si = Silicon) Atomic # Symbol Atomic Mass / Mass # Name

Atomic # Elements are distinguished from each other in the periodic table based on the number of protons in the nucleus

Atomic # is equal to the number of protons (p+) in the nucleus.

Periodic Table Set Up 10.23.2008 Reading Periodic Table Atomic # Atomic # = # protons Atomic # Symbol Atomic Mass / Mass # Name

Atomic # is equal to the number of protons (p+) in the nucleus. Uncharged atoms have the same # of protons & electrons.

Periodic Table Set Up 10.23.2008 Reading Periodic Table Atomic # Atomic # = # protons In uncharged atoms, # protons = # electrons Atomic # Symbol Atomic Mass / Mass # Name

Atomic # The atomic # is 6. What is the number of protons? 6 protons What is the # of electrons? 6 electrons

Periodic Table Set Up 10.23.2008 Reading Periodic Table Atomic # Atomic # = # protons In uncharged atoms, # protons = # electrons Ex. Carbon: Atomic # = 6, # p+ = 6, # e- = 6 Atomic # Symbol Atomic Mass / Mass # Name

Mass # Another way to distinguish elements is by their total mass. Mass # = # protons + # neutrons Why doesn’t the mass # include the electrons? Electrons have an extremely small mass that barely contributes to the overall mass!

Periodic Table Set Up 10.23.2008 Atomic # Mass # Atomic # = # protons In uncharged atoms, # protons = # electrons Ex. Carbon: Atomic # = 6, # p+ = 6, # e- = 6 Mass # = # protons + # neutrons

Ex. 1: If an atom has 5 protons and 5 neutrons, what is the mass #? Mass # = 5p+ + 5n0 = 10

Periodic Table Set Up 10.23.2008 Atomic # Mass # Atomic # = # protons In uncharged atoms, # protons = # electrons Ex. Carbon: Atomic # = 6, # p+ = 6, # e- = 6 Mass # = # protons + # neutrons Ex 1: 5p+ , 5n0  mass # = 10

# neutrons = mass # - # protons = 17-8 = 9 Ex. 2: If an atom has a mass # of 17 and has 8 protons, what is the number of neutrons in the atom? # neutrons = mass # - # protons = 17-8 = 9

Periodic Table Set Up 10.23.2008 Atomic # Mass # Atomic # = # protons In uncharged atoms, # protons = # electrons Ex. Carbon: Atomic # = 6, # p+ = 6, # e- = 6 Mass # = # protons + # neutrons Ex 1: 5p+ , 5n0  mass # = 10 Ex 2: Mass # = 17, 8p+  #n0 = 17-8=9

Mass # Ex. 3: If an atom has a mass # of 22 and an atomic # of 11, what is the number of neutrons? Atomic # = # protons = 11 # neutrons = mass # - # protons = 22-11 = 11

Periodic Table Set Up 10.23.2008 Atomic # Mass # Atomic # = # protons In uncharged atoms, # protons = # electrons Ex. Carbon: Atomic # = 6, # p+ = 6, # e- = 6 Mass # = # protons + # neutrons Ex 1: 5p+ , 5n0  mass # = 10 Ex 2: Mass # = 17, 8p+  #n0 = 17-8=9 Ex 3: Mass # = 22, Atomic # = 11  #n0 = 22-11 = 11

Summary Take a few minutes to make a summary of today’s notes. When done, work on your HW Packet!