Part 1 – Properties of Matter Matter and Change Part 1 – Properties of Matter

Properties and Changes in Matter Every substance has characteristic properties. Chemists use these properties to distinguish between substances and separate them.

Extensive vs. Intensive Properties Properties are either extensive or intensive. Extensive Properties depend on amount of matter present volume, mass, and amount of energy in a substance Intensive Properties do not depend on amount of matter present melting point, density, ability to conduct electricity, and percent composition

Properties of One Penny Metal Composed of 2.5% copper and 97.5% zinc Mass – 2.50 grams Volume – 0.442 mL Density – 5.66 g/mL

Properties of Many Pennies Metal Composed of 2.5% copper and 97.5% zinc Mass – 2500 grams (1000 pennies x 2.5 g) Volume – 442 mL (1000 pennies x.442mL) Density – 5.66 g/mL One Thousand Pennies

Extensive vs. Intensive Properties WHICH PROPERTIES REMAINED THE SAME? Metal Percent Composition Density The intensive properties remained the same because they do not depend on the amount of pennies present.

Extensive vs. Intensive Properties WHICH PROPERTIES CHANGED? Mass Volume The extensive properties changed because they do depend on the amount of pennies present.

There are 2 major categories that all properties of matter fall into Property Types Physical There are 2 major categories that all properties of matter fall into Chemical

They can be observed by using the five senses. Physical Properties Physical properties are characteristics that can be observed or measured without changing the identity of a substance. They can be observed by using the five senses.

What are the physical properties of a labradoodle? Cross between a lab and a poodle Size of a lab With the curly hair of a poodle Can be black, yellow, brown, or white Tail of a lab

Chemical Properties Chemical properties relate to a substance’s ability to undergo changes that transform it into different substances.

Examples of chemical properties: Conductivity -ability to conduct electricity Flammability – ability to ignite Electronegativity – the ability to retain electrons

Part 2 – Changes in Matter

Physical Change A change in the physical appearance of a substance that does not change the identity of the substance. SOLID LIQUID GAS

Physical Changes Still H2O in every form!!! Phase Change – physical change from one state to another SOLID Below 0°C LIQUID Between 0°C and 100°C GAS Above 100°C Only the temperature changes Still H2O in every form!!!

Physical Changes Examples of physical changes: Cutting your hair Crushing an aluminum can Cutting your hair Shredding paper

Chemical Changes Chemical changes, or chemical reactions, occur when one or more substances is converted into another substance. Original atoms are preserved New substances are formed Different chemical composition than original substance

Chemical changes are chemical reactions. Indicated by a number of signs formation of a gas, formation of a solid, or precipitate change in temperature evolution of heat and light Change in color Change in odor

Chemical Changes When iron (Fe) rusts, you can see it happen over a long period of time. The actual iron molecules change their structure as they react with oxygen and are oxidized.

Chemical Changes Grass growing Frying an egg Examples of chemical changes: Milk souring Grass growing Frying an egg

Energy Transfer All changes (physical and chemical) involve some transfer of energy. Body uses energy from chemical reactions to digest food. Weather involves a transfer of energy to evaporate water in the atmosphere. Therefore, the study of matter also involves the study of energy.

Summary Extensive Properties Intensive Properties Physical Properties and Changes Chemical Properties and Changes Transfer of Energy