Chapter 2: Matter Sections 2.2 & 2.3

2.2 Properties of Matter Objectives To learn to distinguish between physical and chemical properties To learn to distinguish between physical and chemical changes

Physical Property Characteristic of a substance that can change without changing the substance’s composition.

Physical Change A change that does not affect the composition of a substance

Examples of Physical Changes Melting/ Freezing Vaporizing/ Condensing Cutting Grinding Squishing

Chemical Property Characteristic that describes the ability of a substance to change into a different substance.

Chemical Change Change in which a substance becomes a different substance.

Examples Flammability (burning) Exploding Fermenting Digesting Corroding Tarnishing Rusting

Evidence of a chemical change

Evidence of a chemical change Formation of bubbles Formation of a precipitate (a solid) A color or odor change Heat, Cold and/ or light evolves

2.3 Classifying Matter Objectives To learn to distinguish between mixtures and pure substances. To learn two methods of separating mixtures.

Mixtures and Pure Substances Defined as something w/ a variable composition. Examples: Soda – water, sugar, carbon dioxide Sea water – water, minerals, salt, etc. 14 carat gold – 36% gold, 25% silver, 37% copper Dirt Air – nitrogen, oxygen, argon, helium, neon, carbon dioxide, water vapor, etc.

2 Types of Mixtures Homogeneous Mixture: mixture that is the same throughout. Can also be called… solutions! Heterogeneous Mixture: mixture containing regions of varying composition.

Heterogeneous or Homogeneous Mixture?

Separation of Mixtures Mixtures can be separated utilizing each substances physical properties. There are several ways to separate mixtures… Use a magnet FILTRATION DISTILLATION Picking it out

Distillation A separation process that depends on the different boiling points of the substances.

Filtration Separation of a solid from a liquid by using filter paper.

Mixtures and Pure Substances Always has the same composition, no matter what! Can be Elements See Periodic Table Compounds There are millions!!!!!! H2O, NaOH, Al2(SO4)3, NaCl, C6H12O6