matter and change mrs. harvey - chemistry - ghs - 2010
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Matter and Change
Mrs. Harvey - Chemistry - GHS - 2010
What is Matter?
Matter- anything that has mass and takes up space.
Mass- measure of the amount of matter
NOT Weight – it is due to gravity, and changes from location to location; mass is always constant.
Mrs. Harvey - Chemistry - GHS - 2010
Properties
Physical Properties- a property that can be observed and measured without changing the composition.
Examples- color, hardness, m.p., b.p.
Chemical Properties- a property that can only be observed by changing the composition of the material.
Mrs. Harvey - Chemistry - GHS - 2010
Physical ChangeA change in a substance that does not involve a change in the identity of the substance.
Example:
Phase Changes
Mrs. Harvey - Chemistry - GHS - 2010
Phase Differences
Solid – definite volume and shape; particles packed in fixed positions.Liquid – definite volume but indefinite shape; particles close together but not in fixed positionsGas – neither definite volume nor definite shape; particles are at great distances from one anotherPlasma – high temperature, ionized phase of matter as found on the sun.
Mrs. Harvey - Chemistry - GHS - 2010
Three Phases
Mrs. Harvey - Chemistry - GHS - 2010
Copper Phases - Solid
Mrs. Harvey - Chemistry - GHS - 2010
Copper Phases - Liquid
Mrs. Harvey - Chemistry - GHS - 2010
Copper Phases – Vapor (gas)
Mrs. Harvey - Chemistry - GHS - 2010
States of Matter
Solid
Liquid
Gas
Definite Volume?
YES
YES
NO
Definite Shape?
YES
NO
NO
Temp. increase
Small Expans.
Small Expans.
Large Expans.
Com-pressible?
NO
NO
YES
Mrs. Harvey - Chemistry - GHS - 2010
Solid Liquid Gas
Melt Evaporate
CondenseFreeze
SUBLIMATION
Mrs. Harvey - Chemistry - GHS - 2010
Chemical ChangeA change in which one or more substances are converted into different substances.
Heat and light are often evidence of a chemical change.
Mrs. Harvey - Chemistry - GHS - 2010
Types of Matter
Substance- pure matter that is uniform (all the same) and has a definite composition (examples are elements & compounds)
Mixture- more than one kind of matter; has a variable composition
Mrs. Harvey - Chemistry - GHS - 2010
Classification of Matter
Mrs. Harvey - Chemistry - GHS - 2010
MixturesPhysical blend of at least two
substances; variable compositionHeterogeneous- mixture is not
uniform in compositionChocolate chip cookie, gravel, soil.Homogeneous- same composition
throughout; called “solutions”Kool-aid, air, salt waterEvery part keeps it’s own properties.
Mrs. Harvey - Chemistry - GHS - 2010
Separation of a Heterogeneous Mixture
The constituents of the mixture retain their identity and may be separated by physical means.
Mrs. Harvey - Chemistry - GHS - 2010
Solutions
Homogeneous mixtureMixed molecule by moleculeCan occur between any state of
mattergas in gas; liquid in gas; gas in liquid;
solid in liquid; solid in solid (alloys), etc.
Mrs. Harvey - Chemistry - GHS - 2010
Solutions
Like all mixtures, they keep the properties of the components.
Some can be separated easily by physical means: rocks and marbles, iron filings and sulfur
Other methods: distillation- takes advantage of different boiling points
Mrs. Harvey - Chemistry - GHS - 2010
Separation of a Homogeneous Mixture
Distillation
Mrs. Harvey - Chemistry - GHS - 2010
Classification of Matter
Mrs. Harvey - Chemistry - GHS - 2010
The smallest unit of an element that maintainsthe properties of that elementElement
A pure substance made of only one kind of atom
Atom
Mrs. Harvey - Chemistry - GHS - 2010
A substance that is made from the atoms of two or more elements that are chemically bonded.
Sucrose – C12H22O11
Sucrose is also known as table sugar, and is used to make Gummy Bears!
Compound
Mrs. Harvey - Chemistry - GHS - 2010
Separation of a CompoundThe Electrolysis of water
Water Hydrogen + Oxygen
H2O H2 + O2
Reactant Products
Compounds must be separated by chemical means.
With the application of electricity, water can be separated into its elements
Mrs. Harvey - Chemistry - GHS - 2010
Compound or Mixture
Compound Mixture
Made of one kindof material
Made of more thanone kind of material
Made by a chemical change
Made by a physical change
Definitecomposition
Variablecomposition
Mrs. Harvey - Chemistry - GHS - 2010