Transcript BondingBasics11

1. How would you define a compound? Use some key
vocabulary terms from the first chemistry test to
help you.
2. If H2O and H2O2 are both compounds, how are they
different?
3. How do atoms combine to form compounds?
4. How do ionic bonds and covalent bonds differ? How
are they the same?
5. Think back to our global warming project. What
compounds (greenhouse gases) have we already
studied? Explain how the electrons move in order
for each of the greenhouse gases to form. Label
each greenhouse gas as an ionic or covalent bond.
8th Grade Science
Adapted from
http://sciencespot.net/
Section A: Complete the chart using a periodic table to help you.
Answer these questions:
NEGATIVE
An atom that gains one or more electrons will have a ____________________
charge.
POSITIVE
An atom that loses one or more electrons will have a ____________________
charge.
ION
An atom that gains or loses one or more electrons is called an ____________.
CATION and a negative ion is called an
A positive ion is called a ______________
ANION
_______________.
“Cat-Eye-On”
“An-Eye-On”
What is an ionic bond?
Atoms will transfer one or more ________________
ELECTRONS to another to form the bond.
COMPLETE outer shell.
Each atom is left with a ________________
An ionic bond forms between a ___________
METAL ion with a positive charge and a
________________
NONMETAL ion with a negative charge.
Example B1: Sodium + Chlorine
Example B2: Magnesium + Iodine
Example B3: Potassium + Iodine
Example B4: Sodium + Oxygen
Example B5: Calcium + Chlorine
Example B6: Aluminum + Chlorine
What is a covalent bond?
Atoms ___________
SHARE one or more electrons with each other to form the bond.
COMPLETE outer shell.
Each atom is left with a ________________
NONMETAL
A covalent bond forms between two _________________.
Example C1: Hydrogen + Hydrogen
Example C2: 2 Hydrogen + Oxygen
Example C3: Chlorine + Chlorine
Example C4: Oxygen + Oxygen
Example C5: Carbon + 2 Oxygen
Example C6: Carbon + 4 Hydrogen
Bond With A Classmate
1. Purple = Cations ; Pink = Anions
2. Find a classmate to “bond” with and together
decide on the correct chemical formula (use
the oxidation numbers to help you!)
3. You will have to decide how many of each ion
you need to make a STABLE IONIC BOND.
4. Record all bonds on your Date Book (data
table)
5. Look at the box on your paper for helpful hints
6. You will have 5 minutes to make as many
bonds as possible.
Review Vocab…
• What is an oxidation number?
• How is it determined?
• What is a subscript? What does it tell you
about the atoms in the compound?
• What is a chemical formula?
Oxidation Numbers
• Same thing as typical charge an atom will have
once it has lost or gained electrons
• Shortcut to writing chemical formulas:
1. Ca
I
2. Ca+2
I13. Ca+2
I1-
Ca1
I2
CaI2
What about Magnesium and
Oxygen?
Oxidation #’s Backwards
Give me the oxidation state (charge) for each
atom (polyatomic ion) in the compound for the
following chemical formulas:
A. Zn(OH)2
B. BeSO4
C. Mg3P2
D. MgBr2
E. KCl
F. NH4OH
1. Metal and nonmetal: Name the metal and
change the nonmetal to –ide
2. Transition metals and nonmetals: Use roman
numerals to represent the charge and name
the nonmetal using –ide
3. Polyatomic Ions : If positive are more like
metals and come first, if negative are more like
nonmetals and come second. They have their
own names and oxidation numbers (see chart
on back)
Naming Ionic Bonds Practice
1. What is the chemical formula for the
compound that results when
Magnesium and Chlorine combine? Use
the lewis dot structures and the criss
cross method to show how you get the
same formula.
2. How do you name this compound?
Show me the formula
1.
2.
3.
4.
5.
Ammonium Chloride
Potassium Nitrate
Calcium hydroxide
Sodium Oxide
Copper (II) Sulfate
Name that Compound…
1.
2.
3.
4.
5.
NaCl
NaCO3
NaOH
NH4OH
Fe2(SO4)3
Naming Covalent Compounds
Guidelines for Inorganic Compounds
1. In covalent compounds, the least
electronegative element comes
first and its name is unchanged.
2. The more electronegative element comes
second and takes on the
–ide ending like in ionic bonds
3. Subscripts are represented by
Greek prefixes
Example: H2O –dihydrogen monoxide
1
Mono-
2
Di-
3
Tri-
4
Tetra-
5
Penta-
6
Hexa-
7
Hepta-
8
Octa-
9
Nona-
10
Deca-
Name that Compound
Can you use the inorganic guidelines for all of
these?
1. CO2
2. N2O
3. N2O4
4. CH4
Show me the formula
1.
2.
3.
4.
5.
hexaboron silicide
chlorine dioxide
hydrogen iodide
iodine pentafluoride
dinitrogen monoxide