definitions what is matter? anything that takes up space and has mass what is mass? measure of the...
TRANSCRIPT
Definitions
• What is matter?• Anything that takes up space and has mass
• What is mass?• Measure of the number of atoms in an object
• What is an element?• A single type of atom – defined by its number of
protons
• What is a compound?• Two or more elements chemically combined
• What is a molecule?• The smallest unit of a compound
Structure of the Atom
• Nucleus – central part of an atom (contains Protons(+) and Neutrons(0)
• Orbitals or Electron Cloud – area where electrons orbit the nucleus (contains Electrons(-))
The Periodic Table of Elements
• First created by DIMITRI MENDELEEV
Periodic Table
PERIODS (or rows)
GRO (or columns)UPS Elements are arranged with
similar properties !
SYMBOL
Atomic Mass #
Atomic #
• Atomic Number = an atoms # of Protons• The # of Protons = # of electrons in a stable atom
• Atomic Mass Number = an atoms # of protons +# of neutrons
• Atomic Mass Units – 1/12 the mass of a carbon atom
SYMBOL
Atomic Mass #
Atomic #
=
# of Protons
=
# of electrons
Protons, Neutrons, and Electrons
ATOMIC MASS – ATOMIC # = Neutrons (4-2) = 2
PracticeGroup # =
Period # =
Atomic # =
Mass # =
# of protons =
# of neutrons =
# of electrons =
Exit Questions
1. Group # =2. Period # =3. Atomic # =4. Mass # =5. # or P+ =6. # of E- =7. # of No =
BOHR MODEL of the atom
• Chlorine• Atomic # 17• Mass # 35• 17 protons• 17 electrons• 18 neutrons
Electron Shells
• 2• 8• 8• 18• 18• 36
Valence Electrons
• Valence Electron – an electron in the outermost electron shell
Draw a simple Bohr model for…• Hydrogen
• Lithium
• Sodium
• How many valence electrons do they have?
Dot Diagrams
Properties of Elements
Metals –Left of the ladderGood conductors, malleable, ductile, solid
Non-metals –Right of the ladderPoor conductors, brittle, most are gasses
Metalloids –On the ladderShare properties of both metals and non-metals
Is it a metal or a non-metal?
• Sodium metal or non-metal• Carbon metal or non-metal• Nitrogen metal or non-metal• Lithium metal or non-metal• Gold metal or non-metal• Oxygen metal or non-metal• Magnesium metal or non-metal• Fluorine metal or non-metal
Stable electron configuration
• Atoms with a complete (filled) outermost electron orbital
• 8 electrons = complete, stable electron orbital
• All the noble gasses have a stable electron configuration
Bonding
• Ionic Bond – Attractive force between a positively charged particle(+) and a negatively charged particle(-) – transfer of electrons – between a metal and a non-metal
• Covalent Bond – Sharing of electrons between two non-metals
Electron Lenders and Borrowers
• METALS – lenders (less than 4 valence electrons)
• NON-METALS – borrowers (more than 4 valence electrons)
• Metal -• Sodium (1 valence electrons) – lends 1 electron becomes +1… in order to
become stable like the noble gasses
• Non-Metal –• Flourine (7 valence electrons) – borrows 1 electron becomes -1… in order to
become stable like the noble gasses
Is it an Ionic or Covalent Bond?
• Magnesium Sulfide Ionic Covalent• Carbon Dioxide Ionic Covalent• Nitrogen Dioxide Ionic Covalent• Lithium Bromide Ionic Covalent• Sulfur Dioxide Ionic Covalent• Barium Oxide Ionic Covalent• Iron Sulfide Ionic Covalent
Ionic Bonds - Review
• TRANSFER OF ELECTRONS
• METALS x Non-METALS
• Metals lend electrons (less than 4)• Non-Metals borrow electrons (more than 4)
Drawing the Ionic Bonds• Magnesium Chloride (MgCl2)
Covalent Bonds - 8
• SHARING OF ELECTRONS
• Non-METALS x Non-METALS
Drawing the Covalent Bonds• Water(H2O)