April 12th and 13th, 2011
Introduction to Chemistry
PERIODIC TABLE SCAVENGER HUNT
DISCUSSION
Q: What is an Atom?
A: The smallest unit of matter
 An atom is does have smaller components (electrons, protons, neutrons, etc). An atom,
however, is the smallest particle of an element that still has the chemical properties of that
element.
 Scientists have found 115 types of atoms so far, and new ones are still being found!
PERIODIC TABLE SCAVENGER HUNT
Q: How many types of atoms can you name?
A: H, C, O, Au, Ag, Na ….
Pass out Periodic Tables and Worksheets and have students work in teams to find the different
elements.
EXPLORING MATTER
DISCUSSION
Q: What is Matter?
A: Anything that has mass and occupies space.
Q: Can you name the forms of matter?
A: Liquid, solid, gas
STATES OF MATTER
Another interesting fact about matter is that it can change its state. Some of the states of matter are liquid,
gas, and solid. There are special names for changing between different states of matter. Can you match
the processes with the correct names?
Process
Scientific Name
LIQUID TO GAS
SUBLIMATION
SOLID TO GAS
FREEZING
GAS TO LIQUID
MELTING
LIQUID TO SOLID
EVAPORATION
SOLID TO LIQUID
CONDENSATION
DISCUSSION
Q: What is chemistry?
A: Chemistry is the science of matter; study how chemicals behave, react, etc. Chemistry
involves all your sense: seeing, hearing, feeling, tasting, and smelling.
Introduction to Chemistry
April 12th and 13th, 2011
EXPERIMENT ONE: EVAPORATION
Goal: In this experiment we will observe different rates of evaporation for water and alcohol.
Since water and alcohol have different atomic structures, they have different physical properties
and evaporate at different speeds. Before we begin, let’s take a moment to consider the two
chemicals we’ll be using. Take a look at the two pictures below and see if you can answer the
following questions:
 Which one is water (H2O) and which one is ethanol (C2H5OH)?
 How many different types of atoms does each molecule contain?
Question/Hypothesis: Will water or alcohol evaporate more quickly?
Procedure:
1. Pass out index cards, have students draw a line down the middle and label one side water and the
other ethanol.
2. Use a pipet to add two drops of water and two drops of ethanol to the appropriate labeled side.
3. Have students time how long it takes for the droplets to evaporate.
Results: Which chemical evaporated the fastest (one sentence)?
Conclusions:
The alcohol evaporated more quickly than the water. Why? The attractive forces between water
molecules are stronger than the attractive forces between alcohol molecules. It takes less energy for
alcohol molecules to overcome these attractive forces and change to the gas state. Chemists say that the
vapor pressure of alcohol is greater than the vapor pressure of water (meaning it takes less energy for
alcohol to become a vapor).
EXPERIMENT TWO: ICE FLOATS AND THE IMPLOADING CAN
Goal: To understand that the chemical structure stays the same, but that the distance between
molecules changes between the three different physical states. What are common names for
water in the three different states? [Ice (s), water (l), steam(g)] Is the chemical structure of water
different in the different states? (No.)
Thought Experiment
Question/Procedure: What will happen when we add ice into a bowl of water?
Hypothesis/Picture:
Conclusions: Solid water is less dense than liquid water. Q: Are solids typically more or less
dense than liquids? (more dense) Then how come ice is solid and less dense? (Order, freely
moving or fixed molecules).
Introduction to Chemistry
April 12th and 13th, 2011
Imploding Can Experiment
Question: What happens to water vapor when it is cooled? (Condenses)
Procedure:
Add two or three tablespoons of liquid water to an empty coke can. Place the can on the heater
and bring the water to a boil (listen—you will hear it bubbling). Let the water boil for another
30-60 sec. The TUTOR should carefully pick up the can with tongs, invert the can over a bowl
of COLD water and quickly drop it into the bowl.
Hypothesis: What will happen when we dump the can of boiling water into the bowl of cold
water?
Results: The can collapsed/imploded/was crushed.
Conclusions:
The heating changed the liquid water into water vapor. Water vapor is less dense (i.e., has more
empty space between molecules) than liquid water. When you dropped the can into cold water,
the vapor condensed back into liquid water and left a partial vacuum (empty space) inside of the
can. The air’s mass exerts forces on the can, which is now empty and unable to counteract these
forces. Hence, the can collapses!
Bonus Question:
What keeps you and me from imploding right now due to all this air pressure?
EXPERIMENT THREE:INERTIA
Goal: To explore the principles of inertia. Inertia is the tendency of a material not to change its
motion or state of rest, and all matter exhibits inertia.
Question: Does a penny have inertia?
Procedure:
1. Lay the index card over the mouth of the cup.
2. Place a penny on top of the card.
3. It should be centered over the mouth of the cup.
Hypothesis: What will happen to the penny when we snap/flick the card with our finger?
Results: What happened to the penny (one sentence)?
Conclusions:
Before you snapped the card, the penny and card were both at rest due to their inertia. Then the
card is snapped from under the stationary coin. The coin simply falls into the cup due to the
force of gravity pulling the coin downwards.