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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.
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Objective • SWBAT explain how the periodic table is set up. • SWBAT identify & calculate atomic number. • SWBAT identify & calculate atomic mass / mass number.
Elements Elements have a characteristic (unique) set of chemical & physical properties. First organized into “periodic table” by Russian Chemist Mendeleev
Elements There is a universally understood symbol for each element. An element is represented in one of 2 ways: 1. A capitalletter Boron: Sulfur: Potassium:
Elements There is a universally understood symbol for each element. An element is represented in one of 2 ways: 1. A capitalletter Boron: B Sulfur: S Potassium: K (from the Latin: Kalium)
Elements There is a universally understood symbol for each element. An element is represented in one of 2 ways: 2. A capitalletter + 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 capitalletter + lowercase letter Calcium: Ca Magnesium: Mg Silicon: Si
Reading Periodic Table Atomic # Symbol Name Atomic Mass / Mass #
Periodic Table Set Up 10.23.2008 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 # Atomic # is equal to the number of protons (p+) in the nucleus.
Atomic # Periodic Table Set Up 10.23.2008 Symbol Atomic Mass / Mass # Name
Atomic # Atomic # is equal to the number of protons (p+) in the nucleus. Uncharged atoms have the same # of protons & electrons.
Atomic # Periodic Table Set Up 10.23.2008 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
Atomic # Periodic Table Set Up 10.23.2008 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!
Mass # Ex. 1: If an atom has 5 protons and 5 neutrons, what is the mass #? Mass # = 5p+ + 5n0 = 10
Mass # 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
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
Summary • Take a few minutes to make a summary of today’s notes. • When done, work on your HW Packet!
