chapter 2. learn about the composition of matter learn the difference between elements and...

Chapter 2

Learn about the composition of matter

Learn the difference between elements and compounds

Learn to distinguish between physical and chemical properties and changes

Learn to distinguish between mixtures and pure substances

Learn to methods of separating mixtures

Can exist in three states – solid, liquid and gas

Can be described in terms of its physical and chemical properties

Matter

Mixture

SubstanceCompound

Element

Heterogeneous

Homogeneous

Suspension

Colloid

Solution

Classification of Matter

Read Chapter 2 Answer the Focus questions at the end of

selected Sections (pages 29 & 41)

Atoms – tiny particles that make up matter

Elements are made of atoms No two elements are made of the same

atoms Made of one type of atom

Compounds are made of molecules that are made of two or more different atoms bonded together A specific compound consists of the same

particles throughout Molecules are made of atoms that are “stuck”

together bonded. CO2 Always have the same composition same

combination of atoms.

1. Oxygen2. Carbon3. Carbon monoxide4. Sugar5. nylon

1. Copper wire2. Silver nitrate3. Lead4. Salt5. Magnesium strips

Describe a substance’s ability to undergo a change to a different substance

Are the characteristics a substance exhibits as long as no chemical change occurs.

Involves a change in one or more physical properties, but no change in composition.

The most common physical changes are changes of state: solid liquid gas

Transforms a substance into a new substance or substances

Involves a change in the fundamental components of the substance A given substance changes into a different

substance or substances Are called reactions

Ex. Silver tarnished by reacting with substances in the air

Ex. A plant form a leaf by combining various substances from the air and soil

Has variable composition Homogeneous mixture (solution)

Has the same properties throughout Ex. tea, sugar water, glass, alloys

Heterogeneous mixture Does not have the same properties

throughout Ex. granite, salt & pepper, Italian

dressing

Two typesElements

Which cannot be broken down chemically into simpler substances

Composed of tiny particles called atoms. Each element has a characteristic type of

atom. All elements are on the Periodic table of

elementsCompounds

Which can be broken down chemically into elements

Are composed of different types of atoms. Contain molecules particles that are

composed of atoms bonded to one another Ex. Sugar, gasoline, baking soda, plastics