Changes in Matter Keisha Kidd, Curriculum Support Specialist Mary Tweedy, Curriculum Support Specialist Millard Lightburn, District Supervisor Department of Mathematics and Science Office of Academics and Transformation Big Idea 9 – SC.4.P.9.1 Pacing Guide 10/14-10/24
Benchmark Descriptions • SC.4.P.9.1 – Identify some familiar changes in materials that result in other materials with different characteristics, such as decaying animal or plant matter, burning, rusting, and cooking.
What is Matter? • Matter is anything that takes up space and has weight. • Matter has three forms. • Matter can be a solid, a liquid, or a gas. • Matter is made up of tiny particles called molecules.
What do we know about solids? • Solids take up space and have mass. • Solids have a shape of their own. • Solids can be described by their physical properties. • Solids can be measured.
What do we know about liquids? • Liquids take up space and have mass. • Liquids do not have a shape of their own. • Liquids take the shape of their container. • Liquids can be measured (mass and volume).
What do we know about gases? • A gas takes up space and has mass. • A gas takes the shape of its container. • A gas is the only kind of matter that always fills all the space inside a container. • The mass of a gas can be measured.
Physical Changes Matter’s appearance may change, however it retains its own properties. Matter can be combined to form: mixtures and solutions
What are some physical properties of matter? • Color • Texture • Odor • Size • Volume • Mass • Solid, Liquid, or Gas • Magnetic • Floats or sinks • Boiling point • Melting point
Physical Changes in Matter • Cutting • Mixing • Shaping • Changing from one state of matter to another. • Melting • Freezing • Evaporating
Mixtures and Solutions A mixture is a combination of two or more components that are NOT chemically combined, and retain their identities. • Mixtures can be physically separated. The identities of the substances DO NOT change. • A mixture is also called a solution.
Mixtures and Solutions • Solutions • A mixture in which all parts are mixed evenly • Can be combinations of gases, liquids, and even solids • http://www.harcourtschool.com/activity/mixture/mixture.html • http://www.chem4kids.com/files/matter_solution.html
What do you know about mixtures? • Form when two or more substances combine. • Keep their physical properties. • Can be separated by their physical properties.
Examples of a mixtures The lettuce and vegetables do not change when mixed Can be separated.
Is cereal a mixture? Yes…the properties of the substances do not change. You can still see the bananas, cereal, and milk.
Substances in a mixture can be separated by their physical properties… So how can we separate this mixture? • Milk and cereal can be separated by pouring the mixture through a strainer.
The cereal would be trapped in the strainer and the milk would pass through.
Is cake a mixture? No…the properties of the substances change. The eggs, flour, and sugar change when the cake is mixed and baked.
QUESTION: Which scientific tool could you use to separate a mixture of iron filings and sand?
ANSWER: You can separate the iron filings from the sand by using a magnet. Iron filings
What do you know now about mixtures? • Form when two or more substances combine. • Keep their physical properties. • Can be separated by their physical properties. • Do not form a new substance.
You can make a special mixture when you stir sugar into water. The sugar dissolves and the water remains clear.
What are solutions? • One of the substances spreads out evenly or dissolves in the other • Solutions are a special kind of mixture
What can be done to speed up or slow down the dissolving process? • Increase the number of and/or force of the stirs. • Change the temperature of the substances being mixed.
Solutions are a special kind of mixture • One of the substances dissolves in the other • The substance spreads out evenly • Solutions may be clear or colored
Solutions A mixture that appears to be a single substance but is composed of particles of two or more substances that are distributed evenly amongst each other. A solution may be liquid, gaseous, or solid. Examples of solutions Liquid - seawater Gas - air Solid - alloys
Do all substances dissolve in liquids? No…if you mix sand with water, the sand does not dissolve but settles on the bottom of the glass. Sand + water water sand
Solutions can be separated • To separate a sugar water solution, let the water evaporate. • Once the water is gone, the sugar will be left. • Most solutions can be separated by evaporation.
All solutions are mixtures but not all mixtures are solutions • Sugar + Water = ? Mixture and a solution • Sand + Water = ? Mixture but not a solution
What do all solutions have in common? • One of the substances in the mixture dissolves in the other substance. • Both substances in the solution retain their properties and can be separated.
What are some other examples of solutions? • Air = 21% Oxygen + 78% Nitrogen + 1% other gases • Soda = Water+ CO2 + other flavors • Jewelry = gold + nickel
What are some physical properties that were used to separate the mixtures? • Color • Size - Volume - Mass • Solid, Liquid, or Gas • Magnetic • Floats or sinks
Evaluation • What is a mixture? Give two examples. • What is a solution? Give two examples. • How do you know when a solid and a liquid form a mixture that is also a solution? • How can mixtures be separated? • How are screen filters and paper filters alike? How are they different?
6. The beaker has a mixture of sugar, sand, and water in it? Which material will collect on the paper towel filter?
Chemical Changes Atoms rearrange and form a new kind of matter.
Other changes in matter • Some changes in matter are reversible. • Some changes in matter are irreversible. • Rusting, burning, and cooking are irreversible changes.
Chemical Changes in Matter Decaying Animals Decaying Plants
Chemical Properties and Changes Chemical changes change the chemical nature and properties of substances to form new substances • A match burns • Two substances mix together turn a color different from either of them • Toasting marshmallows • Melt it—physical change • Burn it—chemical change
Changes in Matter Physical Changes Chemical Changes
All matter has properties, but matter also undergoes changes. Look at a cube of sugar. What are its physical properties? It’s white. It’s shape is a cube. It smells sweet. It’s made of sugar crystals. If you crush it, it will still be sugar. What was changed? Only it’s shape. It is still made up of sweet, sugar crystals. Matter has physical properties that can be observed without changing the type of matter. Matter can also change in ways that do not affect the type of matter. These changes are called physical changes.
Take a piece of paper and change it in some way. How did you change it? • Folding Bending • Tearing Cutting • Crumpling Why are the changes that you all made to the paper just physical changes? The paper is still paper. You can unfold it.
Matter has other properties that cannot be observed without changing its identity. What will happen if I hold a lit match to a piece of paper? Yes, the paper will burn. Observe as I demonstrate lighting a piece of paper with a match. What happened to the paper? The paper changes into ash and smoke. (The smoke is carbon dioxide gas, and water vapor). What kind of change is burning paper? During a chemical change, substances react and form new substances. Did this happen? Yes, burning is a chemical change.
Compare and ContrastProperty Changes Physical change Chemical changes A chemical change is a change in the chemical properties of matter. A chemical change occurs when two or more kinds of matter combine to form a new substance with different properties. A change that takes place when a substance is completely altered. The particles of matter do change. • A physical change is a change in the physical properties of matter. The matter changed in how it looks, but what it is made out of does not change. • A change that takes place when a substance changes in size, shape or form. The particles of matter do not change.
More on Physical Changes What is happening to the ice cubes? • They’re melting. • If you add enough heat energy to ice, it turns into liquid water, then it turns into a gas called water vapor. • If you cool the substance,by taking away heat energy, you can reverse these changes. • You can change a gas into a liquid and a liquid into a solid. • What type of change is this? • Changing from one state to another state is an example of a physical change.
Physical change is often due to a change in temperature How does heat affect physical changes? Some types of matter change state when enough heat is added to it (melting) or taken away from it (freezing). What are some examples of each? Water freezes at 0 ̊ Celsius or 32 ̊ Fahrenheit
Water changes to steam, a gas, when it is heated to its boiling point*, as water vapor cools it condenses back to form a liquid. *Water boils at 100 ̊ Celsius or 212 ̊ Fahrenheit
What are some different ways that matter changes physically? • Crushing • Folding • Bending • Tearing • Cutting • Crumbling • Sanding • Smashing • Peeling • Melting * • Freezing * *A process in which a type of matter changes state when enough heat is added to it (melting) or taken away from it (freezing).
Making Cookies Imagine that you and your mom are making cookies. You mix all the ingredients together in a bowl. Next you spoon out cookie dough onto a baking sheet. Then you place the sheet in a hot oven to bake. The change that turns the dough into a cookie is called a chemical change. Chemical changes are also called reactions.