Carbon: Transformations in Matter and Energy
Environmental Literacy Project
Michigan State University
Systems and Scale
Unit
Unit Map
You
are
here
3
The bottom of flame at atomic-molecular scale
Oxygen
Carbon Dioxide
Water
The top of flame at atomic-molecular scale
Oxygen
Carbon Dioxide
Water
5
What happened between the bottom and the top of the flame?
Bottom of the
flame
Top of the flame
Oxygen
Carbon Dioxide
Water
Oxygen
Carbon Dioxide
Water
Methane
What’s the hidden
chemical change
when methane burns?
Answer each of the questions (numbered 1-4) below to explain how matter and energy move and change in a system. Note that matter movement is
addressed at both the beginning (1) and end (4) of your explanation.
Evidence We
Can Observe
BTB can indicate CO2 in the air.
Organic materials are made up of molecules containing carbon atoms:
• fuels • foods • living and dead plants and animals
•decomposers
Question
What is happening
to energy?
What forms of energy are involved?
What energy transformations take place during the chemical change?
Evidence We
Can Observe
We can observe indicators of different forms of energy before and after chemical changes:
• light energy • heat energy • chemical energy stored in organic
materials
• motion energy
Rules to Follow
All materials (solids, liquids, and gases) are made of atoms that are bonded together in molecules.
Scale: The matter movement question can be answered at the atomic-molecular, cellular, or macroscopic scale.
Question
Where are molecules
moving?
How do molecules move to the location of the chemical change?
How do molecules move away from the location of the chemical change?
Evidence We
Can Observe
Moving solids, liquids, and gases are made of moving molecules. A change in mass shows that molecules are moving
.
Question
How are atoms in molecules
being rearranged into
different molecules?
What molecules are carbon atoms in before and after the chemical change? What other molecules are involved?
Rules to Follow
Atoms last forever in combustion and living systems.
Atoms can be rearranged to make new molecules, but not created or destroyed.
Carbon atoms are bound to other atoms in molecules.
Scale: The matter change question is always answered at the atomic-molecular scale.
Rules to Follow
Energy lasts forever in combustion and living systems.
Energy can be transformed, but not created or destroyed.
C-C and C-H bonds have more stored chemical energy than C-O and H-O bonds.
Making the Reactant Molecules: Methane and
Oxygen
The flame of burning methane comes when methane (CH
4
) reacts with
oxygen (O
2
). Make a molecules of methane and oxygen on the reactant side
of your
Process Tool for Molecular Models 11 x 17 Poster:
1. Get the atoms you will need to make your molecules. Can you figure out
from the formula for methane how many C, H, and O atoms you will
need?
2. Use the bonds to make models of an methane molecule (CH
4
) and at
least 2 oxygen molecules (O
2
, with a double bond)
3. Identify the
high-energy bonds
(C-C and C-H) by putting twist ties on
them. How many high energy bonds does a molecule of methane have?
4. Compare your molecules to the pictures on the next slide. Are they the
9
Photo of reactant molecules: CH
4
(methane) and O
2
(oxygen)
Start by making the molecules and energy units of the reactants and putting them on the
reactants side, then rearrange the atoms and energy units to show the products.
Remember:
Atoms last foreve
r (so you can rearrange atoms into new molecules, but can’t add or
subtract atoms).
Energy lasts forever
(so you can change forms of energy, but energy units can’t
appear or go away)
Reactants
Products
Chemical
change
Important:
When you are
finished constructing
the reactants, put all
Rearranging the Atoms to Make Product
Molecules: Carbon Dioxide and Water
The flame of burning methane comes when methane (CH
4
) reacts with oxygen (O
2
)
to produce carbon dioxide (CO
2
) and water (H
2
O). Show how this can happen:
1. The heat of the flame breaks the bonds in the molecules, so their bonds can
break. Now they can recombine into carbon dioxide (CO
2
) and water vapor
(H
2
O). Make as many of these molecules as you can from one methane
molecule and oxygen.
2. Figure out numbers of molecules:
a) How many O
2
molecules do you need to combine with one methane molecule?
b) How many CO
2
and H
2
O molecules are produced by burning one molecule?
3. Remember,
atoms last forever.
So you can make and break bonds, but you still
need the same atoms.
4. Remember,
energy lasts forever.
What forms of energy do the twist ties
represent now?
5. Compare your molecules to the pictures on the next slide. Are they the same?
Photo of product molecules: H
2
O (water) and CO
2
(carbon dioxide)
Start by making the molecules and energy units of the reactants and putting them on the
reactants side, then rearrange the atoms and energy units to show the products.
Remember:
Atoms last foreve
r (so you can rearrange atoms into new molecules, but can’t add or
subtract atoms).
Energy lasts forever
(so you can change forms of energy, but energy units can’t
Reactants
Products
Chemical
change
Water
13
Comparing photos of reactant and product molecules
Start by making the molecules and energy units of the reactants and putting them on the
reactants side, then rearrange the atoms and energy units to show the products.
Remember:
Atoms last foreve
r (so you can rearrange atoms into new molecules, but can’t add or
subtract atoms).
Energy lasts forever
(so you can change forms of energy, but energy units can’t
appear or go away)
Reactants
Products
Chemical
change
Water
Carbon
dioxide
Reactants
Products
Chemical change
What happens
to atoms and energy
when methane
burns?
Methane
Reactants
Products
Chemical change
Oxygen
Water
Heat and light energy
Carbon Dioxide
What happens
to carbon atoms
when methane
burns?
Methane
Carbon atoms in
methane become
part of carbon
dioxide molecules.
Reactants
Products
Chemical change
Water
Carbon Dioxide
Methane
What happens
to oxygen atoms
when methane
burns?
Oxygen atoms
become part of
carbon dioxide and
Reactants
Products
Chemical change
Oxygen
Water
Heat and light energy
Carbon Dioxide
Methane
What happens
to hydrogen atoms
when methane
burns?
Hydrogen atoms
become part of
water molecules.
Reactants
Products
Chemical change
Water
Carbon Dioxide
Methane
What happens
to chemical energy
when methane
burns?
Chemical energy is
transformed into heat
Reactants
Products
Chemical change
