ChemistryChapter 6

Chemistry

What is chemistry? The study of matter. Questions that chemistry is trying to

answer:▪ What is matter made of?▪ How does matter behave?▪ How is matter combined or taken

apart?

Chemistry

What is matter? Any substance that has mass and

volume (takes up space)

Matter is the “stuff” that makes up the universe.

Matter always has certain properties (characteristics or features).▪ There are two types of properties…

Chemistry

Physical properties: Any feature that can be directly observed

without changing the chemical structure:▪ Colour▪ Texture▪ Smell▪ Density▪ Conductivity▪ Solubility

Chemistry

Chemical properties: Properties that describe how it will react

when combined with another substance to form a new substance with new properties.

Classifying Matter

Matter

Pure Substances Always have identical properties in every sample every time Homogeneous: have the same properties throughout the sample Made of only 1 kind of particle

Mixtures 2 or more substances put together but not chemically combined Often heterogeneous: different kinds of particles with different properties in the same sample

Pure Substances

Elements: Pure substance made of only 1 kind of

atom Has its own unique atom Cannot be broken down into simpler

substances Always has a name in English or Latin Always has a symbol▪ i.e. K – Potassium, Na – Sodium, Hg -

Mercury

Pure Substances

Compounds: Pure substance made of 2 or more

elements bonded together in a fixed proportion!

Smallest part is a molecule Can be broken down with energy Always has a formula▪ i.e. CuCl2, H2O2, H2CO3

Mixtures

Solutions: Mixture in which one part has dissolved

and spread out evenly in another part Always homogenous i.e. salt water, coffee, CuCl2 (aqueous)

Mixtures

Mechanical Mixtures: Mixture in which one part is mixed with

another part, but each part retains its own identity

Easily separable i.e. iron filings and sulfur, raisin bran

Mixtures

Suspensions and Colloids: A suspension is a mixture in which one

part rises to the top while the other sinks to the bottom (heterogeneous). i.e. orange juice, salad dressing.

A colloid is a mixture in which the parts never settle out (a stable suspension). i.e. homogenized milk, mayonnaise,

Pure Substance or Mixture?

1. 2.

Pure Substance or Mixture?

3. 4.

Pure Substance or Mixture?

5.

6.

Pure Substance or Mixture?

7. 8.

Assignment

C.Y.U. 6.1 on page 152 in your textbook. # 1, 2, 3, 4, 5, 6, 9, 10