What is Chemistry The science that investigates and

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What is Chemistry?

What is Chemistry?

 • The science that investigates and explains the structure and properties and matter

• The science that investigates and explains the structure and properties and matter

What is matter? • Anything that takes up space and has mass • Books,

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.

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

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

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.

We classify matter by composition • Using qualitative and quantitative observations.

Qualitative observations • Are observations that can be made without measurement… • Make a

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

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

• 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

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

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

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

• 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

• 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

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 changes take advantage of the physical properties of a mixed substance.

Physical Properties • Are characteristics of a sample of matter that can be observed

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.

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.