Transcript stable structure - Rothschild Science

How do compounds form?
Bonding
Knowledge Rating
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TKI
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Valence electrons
Electron dot structures
Octet rule
Anion
Cation
Ionic Bond
Metallic Bond
Halide ion
Write your own definition of each term!
4 things can happen when elements
come together to form
compounds?
1.
2.
3.
4.
Atoms can lose electrons
Atoms can gain electrons
Atoms can share electrons
Share pooled electrons
Jerry Springer
Chemistry
Sick, Sick, Sick!!
Otherwise known as
Ionic Bonding
Metals are easy1. give up valence electrons
2. become positively charged
Nonmetals are users
1. take valence electrons whenever
possible
2. become negatively charged
First- Let’s draw the Bohr
model for Na and Cl
How many valence electrons does each
element have?
What happens when the metal looses his
electron?
What happens when Cl gains and electron?
What do we know about the
stability of Nobel gases?
Octet rule- atoms in compounds tend
to have the electron configuration of
a nobel gas.
A Really Long Song...
Want to learn an easier way of drawing
valence electrons around atoms?
Lewis Dot structures- Write the
symbol and the electrons (in their
correct spots!)
Let me show you sodium and chlorine!
Now you try
1. Magnesium
2. Oxygen
3. Fluorine
4. Potassium
5. Phosphorous
I forget… how can I
tell how many
valence electrons
are in a group?
Oxidation Numbers
Just a fancy name for the charge---It’s the number of valence
electrons an atom wants to give up--or receive to achieve a nobel gas
configuration
Write these
somewhere!!!!
Magnesium Sulfide
• Draw the LS for Magnesium
• How many electrons can it give up?
• Draw the LS for Sulfur
How many empty spots does it have?
Does it make sense that these
two will fit together?
Twins- Kinky!!
• Draw the LS for Calcium
• How many chlorine atoms are needed?
Triplets??
Draw LS for Nitrogen
How many Sodium atoms are needed to
“complete” nitrogen
Name the ionic compound!
Warm Up
a. Draw the Lewis Structures for calcium
and bromine.
b. Identify the type of atom (metal or
nonmetal).
c. Draw arrows to show the movement of
electrons.
We can always tell how many atoms of each
element will form a neutral compound…
Criss Cross method
Work on the Ionic Bonding WS
Naming ionic compounds
• Name the cation (metal)…
….then the anion (nonmetal)
and add “ide”
CaCl2
Let’s practice a few on the IB WS
Important Vocab Terms
Electrostatic force - the force that occurs when a +
charge is attracted to a - charge (causes the
bonds!)
Salt- another name for ionic compounds
Formula unit- One molecule of an ionic compound
Ionic Compounds
Electrostatic attraction between formula
units create a stable structure
“Crystal Lattice”- formula units, which
repeat in a geometric pattern.
NaCl
Properties of Ionic
Compounds
1. Crystalline solids at room temperature
2. Have very high melting and boiling points
3. Conduct electricity when in a molten state (or
dissolved in water)
Warm Up:
How many atoms of each element in the
following compounds??
NaCl
CaCl2
Na3PO4
Ca(NO3)2
Al2(SO4)3
Now you practice!!
How do I calculate
Molar Mass?
1. Determine the number of atoms of
each element.
2. Multiply by the atomic mass.
3. Add’m Up
Ionic Bonding Cut and
Paste Activity
1. Color the cations one color and the anions
another.
2. Build the neutral compounds.
3. Remember your + charges need to equal
the - charges.
4. Name the compounds!
Ionic Bonding with
Polyatomic Ions
Polyatomic Ions- A group of covalently
bonded atoms that have a charge.
The charge is attracted to the charge on a
metal to form an ionic bond.
Polyatomic Ion Rap
Practice….
What about the
Transition Metals?
We need to be a little careful with
these because Transition Metals
often have more than one oxidation
number.