Solid Has Definite Shape and Definite Volume

Matter Matters

Introduction

Overview:

The goal of the unit is to teach students about the properties of matter and its different states. The students will learn definitions of the different states and be able to recognize all of them by their different properties. They will also learn how to identify a chemical reaction by phase changes and about matter that does not fit the accepted definitions of any of the three states.

Background:

Everything is made of matter, and matter comes in three basic states: solid, liquid, and gas. Isaac Newton came up with definitions for the three states:

Solid—has definite shape and definite volume

Liquid—has definite volume but indefinite shape

Gas—has indefinite shape and indefinite volume

These are known as the Newtonian definitions. A solid will keep its shape despite the shape of the container it is placed in, and it will always be the same size. A liquid will take the form of its container, but it always takes up the same amount of space. A gas will fill its container no matter how small or large. This allows for different levels of gas pressure.

The states of matter are dependent of the activity of the molecules that compose them. Molecules act differently at different temperatures. At cooler temperatures the molecules move slowly and are close together. This is a solid state of matter. As it heats up the molecules spread out and move faster, going through the liquid and the solid stages. When the molecules are close together the matter is much denser than when they are spread apart. For this reason, gases always float on top of liquids.

Many chemical reactions can be identified by a phase change. If a solid and a liquid are combined and a gas is released, a phase change occurred. If two liquids are mixed and a solid forms in them, then a phase change has occurred. There are many chemical reactions that include phase changes, such as baking soda and vinegar.

Some matter exists that cannot be classified by the Newtonian definitions of solid liquid and gas. These are called non-Newtonian fluids. These fluids display properties of more than one of the different states of matter (most commonly solid and liquid). They may be solid at some times but liquid under slightly different conditions (temperature is not altered). A common non-Newtonian fluid is corn starch mixed with water or Oobleck. It displays both solid and liquid properties.

Matter Matters

State Standards and Benchmarks

Oregon Standards for 3rd and 5th grade

Science- Collecting and Presenting Data.

Oregon Common Curriculum Goal:

Conduct procedures to collect, organize, and display scientific data.

Benchmarks:

Grade 3: Collect data from an investigation.

Grade 5: Collect, organize, and summarize data from investigations.

Science- Physical Science

Oregon Common Curriculum Goal:

Understanding structure and properties of matter

Benchmarks:

Grade 3: Describe objects according to their physical properties.

Grade 5: Identify substances, as they exist in different states of matter.

Science- Scientific Inquiry

Oregon Common Curriculum Goal:

Formulate and express scientific questions or hypotheses to be investigated

Benchmarks:

Grade 3: Make observations. Based on these observations, ask questions or form hypotheses, which can be explored through simple investigations.

Grade 5: Make observations. Ask questions or form hypotheses based on those observations, which can be explored through scientific investigations

Matter Matters

Vocabulary

· Acid

· Base

· Borax

· Burn

· Carbon Dioxide

· Catalyst

· Chemical Crosslink

· Chemical Reaction

· CO2- Carbon Dioxide

· Color Change

· Combustion

· Condense

· Cornstarch

· Density

· Displacement

· Dissolve

· Endothermic

· Evaporate

· Exothermic

· Float

· Freeze

· Gas

· Gel

· Hydrophilic

· Hydrophobic

· Indicator

· Limiting Reagent

· Liquid

· Mass

· Matter

· Melt

· Newtonian

· Non-Newtonian Fluid

· Oxygen

· Ph

· Phase Change

· Polymer

· Polyvinyl Alcohol

· Pressure

· Properties

· Reaction

· Saturate

· Shape

· Sink

· Sodium Acetate

· Sodium Borate

· Solid

· Soluble

· Sublimate

· Suction

· Super Saturated Solution

· Surface Tension

· Synthetic

· Temperature

· Temperature Change

· Vacuum

· Viscosity

· Volume

Matter Matters

Lesson Index

Lesson:

Balloon Vacuum Demonstration

Candle and Rising Water Demonstration

Cartesian Diver Demonstration

Crushing Can Demonstration

Density Bottles

Dry Ice Demonstration

Egg in a Flask Demonstration

Floating Golf Ball Demonstration

Gel Beads

Hot/Cold

Inflating Bag Reaction

Liquid Nitrogen Demonstration

Measuring

Mentos Fountain Demonstration

Moving Gas

Page:

“Oobleck”

Silly Putty

Sink or Float Demonstration

Sodium Acetate Towers

Solid Stations

Solid, Liquid, Gas

Straws and Water

Synthetic Snot

Syringes and Gas Pressure

Water Whirlpools Demonstration

Matter Matters

Balloon Vacuum

Grades K-5 (with variations)

Overview:

Students watch as a condensing gas creates a vacuum strong enough to pull a balloon inside a flask.

Time: 15-20 minutes (this was done as a station in the gas rotation)

Materials:

Teaching/demo materials:

· 150 mL flask

· Water

· Hot plate

· Large Balloon

Setup:

Set the hot plate and other materials at the station table. Either Pour about 1 cm of water into the bottom of the flask and begin to boil it on the hot plate before the students arrive or heat a small amount of water (a small amount works best because the temperature can change quickly) in the microwave, if you would like the balloon to inflate before it gets sucked into the flask..

Background:

When water boils it is converted from liquid water into water vapor, which is a gas. Gas is much less dense than liquids, so the same number of molecules take up much more space in gas than in liquid form. If a gas is cooled to a liquid inside a sealed container it will create a vacuum because the liquid takes up less space than the gas. As nature attempts to create pressure equilibrium there will be inward force on the container since the pressure outside is much greater than that inside.

Activities/procedure:

Heat a small amount of water in a flask (microwave works fine). The water does not need to be brought to a boil. Then put a balloon around the opening of the flask, creating a seal. When the flask is put on a hot plate, the balloon will inflate with water vapor. When the flask is submerged in room temperature water, the water in the flask will cool and the vapor will condense. This will create a vacuum and the balloon will be sucked inside the flask. Dipping the flask in room temperature water may help to speed the cooling process.

Discussion:

· Talk about properties of matter:

o Liquids are denser than gasses.

o Molecules take up less space in liquid form than in gas form.

o An absence of matter will create a vacuum.

o When a vacuum exists, nature wants to create equilibrium by filling the space; this causes pressure from the outside to push inward.

Vocabulary:

· Gas

· Pressure

· Vacuum

References:

Experiencing Chemistry: Museum Manual Part 1. Portland, Oregon: Oregon Museum of Science and Industry, 1997. 51-54.

Matter Matters

Candle and Rising Water

Grades K-5 (with variations)

Overview:

This is a demonstration to show how a vacuum is created and uses pressure to draw up a liquid.

Time: 5-10 minutes

Materials:

Teaching/demo materials:

· Votive candle

· Clear shallow container

· 3 pennies

· 2000 mL Erlenmeyer flask

· Water

· Food coloring

Setup:

Place three pennies in the bottom of the shallow container far enough apart that the flask can rest upside-down on top of them. Color the water using the food coloring. This is just to make the water more visible to the students. Fill the container with about 1 inch of water. Place the candle between the pennies and the flask over it.

Background:

A candle needs oxygen in order to burn. When it burns it burns the oxygen around it and converts it to carbon dioxide and water, which are both denser than oxygen. This creates a vacuum. In order to create pressure equilibrium, the water is sucked into the flask.

Activities/procedure:

This activity is done as an in-class demonstration. Light the candle and place the flask over the top. The water should be above the mouth of the glass. As the candle burns, the water will rise. Since the candle floats, it will continue to burn until the oxygen is used up.

Discussion:

· Explain the process by which the water is sucked into the flask. (The depth with witch the demonstration is explained will depend on the academic level of the class. The most important concept is that the burning candle creates a vacuum which sucks up the water.)

Vocabulary:

· Burn

· Oxygen

· Vacuum

References:

Gibson, Gary. Science for Fun: Experiments with Easy-to-Make Projects on Magnets, Sound, Light, Electricity, and Much, Much More. Brookfield, Connecticut: Aladdin Books Ltd, 1996. 108-109.

Matter Matters

Density Bottles

Grades K-5 (with variations)

Overview:

In this activity the students will explore the densities of different liquids.

Time: 15-20 minutes (this was done as a station in the liquid rotation)

Materials:

For each group:

· Clear 20-oz. Bottle

· Water

· Corn syrup

· Vegetable oil

· Food coloring

· 3 medium beakers (1 for each liquid)

· 3 small beakers (1 for each liquid)

· 6 droppers (2 for each liquid)

· Waste container

· Sponge

Teaching/demo materials:

· Pre-made density bottles

· Ocean (or other) decoration using density layers (optional)

· Cartesian Diver

Setup:

Set the density bottles and demonstrations on the station table along with the empty bottle, the corn syrup, and the oil. Fill a flask with water and color it with food coloring. Place it on the table as well. Place three small beakers on each table, one for each liquid, and place 2 droppers in each beaker.

Background:

Some liquids are denser than others. In a bottle with liquids of varying densities, the densest liquid will sink to the bottom. This is because it weighs more per volume, so it sinks. If the liquids are soluble with each other, they will eventually dissolve together, but if the liquids are not soluble in each other (such as water and oil) there will be distinct and lasting layers.

Activities/procedure:

Give the students a few minutes to explore the density bottles on the table. Ask questions about the relative densities of the liquids in the bottles. Once they have seen all the bottles, help the students make their own density bottle using corn syrup, water, and oil. Let the students decide which they think is the densest and should be poured in first. Have them do this by experimenting dropping drops of the different liquids on top of each other. The densest should be the corn syrup. Have them decide which should be poured in second and third. If they are wrong about which is the densest the layers should switch places. This can be a little difficult for the corn syrup because it is slightly soluble in water, so try to get the students to pick it to be poured in first. The density bottle should have corn syrup on the bottom, colored water in the middle, and oil on the top. If shaken, the corn syrup will eventually dissolve in the water.

Discussion:

· Which layer is the densest? (the bottom layer)

· Which layer is the least dense? (the top layer)

· Is the water more or less dense than the corn syrup? (less)

Continue these types of questions until the students are confident that they understand density.)

Extension: If the group grasps the concept quickly they can continue on to these topics:

o Solubility

o Hydrophobic (does not dissolve in water) vs. hydrophilic (dissolves in water)

Vocabulary:

· Density

· Hydrophilic

· Hydrophobic

· Soluble

References:

Experiencing Chemistry: Museum Manual Part 1. Portland, Oregon: Oregon Museum of Science and Industry, 1997. 1.39-1.44

Matter Matters

Dry Ice

(Identical to the Chemistry Lesson)

Grades K-5 (with variations)

Overview:

These demonstrations familiarize students with dry ice and its properties, and help to teach them about different states of matter. They allow students to make connections with the use of dry ice in the real world. Dry ice is a potentially dangerous substance so precautions should be taken.

Time: 45-60 minutes

Materials:

For the exploration:

· Cup of water

For Screaming Metal:

· Metal spoon

· water

For Fire Extinguisher

· Candle

· Matches

· Cup of water

For Balloon Magic

· Balloon

· Hot water

For Soap Experiment:

· Soap*

· Hot water

· Plastic container

*Note: this can be made with a homemade bubble solution (dish soap + water + glycerin or mineral oil) being substituted for the soap and hot water.

For Bubbles:

· Bubbles and wand

· Hot water

· Plastic container

For the class:

· Heavy Duty gloves

· Hammer (if ice doesn’t come in pellets)

· Tongs for handling the ice

· Food coloring

Demo:

· Cabbage juice

· Graduate cylinder (large)

· Ammonia

Setup:

This is easy to set up in table groups, with each group having the materials for all the experiments except the bubble and soap experiments. Remember to start heating hot water before the exploration time and have the soap already in the container when you go to do the demonstration.

Inform students of the dangers of dry ice! Make sure to tell them that regular H2O steam will burn badly. Even though this looks like steam, it is not. It is safe to touch CO2 gas.

Background:

Humans exhale gaseous carbon dioxide (CO2), but what does carbon dioxide look like as a solid? It is dry ice. Just like water, carbon dioxide must be frozen to become a solid. It freezes at -109ºF or -80ºC, which is much colder than the 0ºC at which water freezes, so it can be very dangerous. Dry ice undergoes sublimation, a direct change from a solid to a gaseous state without becoming a liquid. Dry ice burns in the same way that boiling water will burn the skin and can cause frostbite, ice crystals form under the skin and cause tissue damage just like a burn, when touched for long periods of time. Be very careful with the ice and carefully observe the students’ exploration of the ice to ensure safety.