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What is Chemistry?. The science that investigates and explains the structure and properties and matter. What is matter?. Anything that takes up space and has mass Books, pencils, water, air… It is not… The heat and light from a lamp Radio waves Thoughts or ideas. Mass is….
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The science that investigates and explains the structure and properties and matter
What is matter? • Anything that takes up space and has mass • Books, pencils, water, air… • It is not… • The heat and light from a lamp • Radio waves • Thoughts or ideas
Mass is… • The measure of the amount of matter that an object contains.
The structure of matter… • Refers to its composition (what it is made of and how it is organized)
Properties of matter… • Describe the characteristics and behavior of matter-including the changes that matter undergoes.
We classify matter by composition • Using qualitative and quantitative observations.
Qualitative observations • Are observations that can be made without measurement… • Make a qualitative observation…
Quantitative observations • Are observations that use measurements • An example of a quantitative observation is the temperature or your height.
Using these observations we can tell if the substance is pure or a mixture
Pure Substances… • Pure means that every bit of the matter being examined is the same substance • A substance is matter with the same fixed composition and properties
A mixture… • Is a combination of two or more substances in which the basic identity of each substance is not changed
Mixtures… • Every particle is not the same, so the properties are not the same throughout • The composition is not fixed, but depends on how much of each part of the mixture is present… • Lemonade
One characteristic of a mixture is that it can be separated into its components by physical processes. • This means that the identity of the substance is not changed by the process • (picking olives off of your pizza)
Mixtures can be separated by picking the pieces apart, but that can be tedious in a mixture like lemonade… • Separating mixtures by using physical changes is an easier way.
Physical Changes • A change in matter that does not involve a change in the identity of the substance • Ex: boiling, freezing, melting, evaporating, dissolving, crstallizing
Physical changes take advantage of the physical properties of a mixed substance.
Physical Properties • Are characteristics of a sample of matter that can be observed or measured without any change in its identity. • Ex: Melting point, boiling point, color, density, electrical conductivity, and physical state
Your turn! • Make two quantitative and two qualitative observations with your lab partner. (Miss Browne has rulers if you need them) • Turn them in before you leave.