CHEMISTRY OCTOBER 20, 2014 ATOMIC CONCEPT ATOMIC NUMBER AND MASS NUMBER
SCIENCE STARTER You are seated and quiet You have 2 minutes Do the SCIENCE STARTER
AIM How do we read the periodic table?
PUZZLES Using the Periodic Table, solve the puzzles. You are given 10 minutes. You may work with a partner. Both partners must be actively participating. I will be walking around grading you on your participation. Stop when you see the stop sign
DEBRIEF So, what is the atomic number? How did you know where to find it? How did you know what is the number of protons? How did you know what is the number of electrons?
VOCABULARY ATOMIC NUMBER MASS NUMBER ATOMIC MASS ATOMIC MASS UNIT PERIODIC TABLE
ATOMIC NUMBER the number of protons that an atom has in its nucleus
MASS NUMBER number of neutrons and protons in an atom for an element
ATOMIC MASS weighted average mass of an atom of an element based on the relative abundance of that element’s isotopes
ATOMIC MASS UNIT unit for atomic mass
PERIODIC TABLE a table of the chemical elements arranged in order of atomic number, usually in rows, so that elements with similar atomic structure (and hence similar chemical properties) appear in vertical columns.
One atomic mass unit 1/12 of the mass of a carbon atom that contains 6 protons and 6 neutrons
AMU Proton = 1 amu Neutron = 1 amu Electron = 0 amu (almost zero so do not count)
READING THE PERIODIC TABLE
Element = Carbon Symbol = C Atomic Number = 6 Atomic Mass = amu Mass Number = 12 Number of Protons = 6 Number of Electrons = 6 Number of Neutrons = 6
TRY IT ElementSymbolAtomic Number Atomic MassMass Number ProtonNeutronElectron Hydrogen Oxygen Krypton Helium Lithium Gold
ElementSymbolAtomic Number Atomic MassMass Number ProtonNeutronElectron Hydrogen H amu1101 Oxygen O amu16888 Krypton Kr amu Helium He amu 4222 Lithium Li36.94 amu7343 Gold Au amu