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)