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Section 2.2 Properties of Matter
• Why are color, volume, and density classified as physical properties?• Why are flammability and reactivity classified as chemical properties?
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What are physical properties?Physical properties are characteristics that can be observed without changing the composition of the substance.
• Physical properties can help identify substances.
• Physical properties can be observed or measured.
What are some of the physical properties of this
football?
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Examples of physical properties: • shape• color• odor• texture• state of matter• melting point• boiling point• strength• hardness• magnetism• ability to conduct electricity or heat
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What is the melting point and boiling point?
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Name that image
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Name that image
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Density• density: the ratio of an object's mass to its volume
density = mass or D = m volume V
• common unit of density is g/cm3
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Which object is MORE dense than water and which
object is LESS dense that water?
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Chemical Properties
• A chemical property describes how a substance changes into a new substance, either by combining with other elements or by breaking apart into new substances.
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• Flammability is a chemical property.
flammability: the ability to burn
• Reactivity is a chemical property.
reactivity: the capacity of a substance to combine chemically with another substance
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Physical and chemical properties are different.
• Physical properties can be observed without changing the composition of a substance.
• Chemical properties can be observed only in situations in which the composition of the substance changes.
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Math Practice on Density
Questions 1, 2, 3 on page 54 AND Questions 5, 6, 7 on page 58