Matter Properties and Classification AP Chemistry Croatan High School Thanks to David English

Matter Matter: Anything that occupies space and has mass Examples of matter include…. Matter does not include ENERGY – Relationship between matter and energy is important

Classification Scientists like to classify what they study – Provides order – Produces a standard language

Classification in Chemistry Chemists study matter so we need a classification system for matter

Kinds of Matter Matter can be subdivided into two types based on how many PHASES exist in the sample

Kinds of Matter Phase : A region of matter with a set of unique properties and definite boundaries

Kinds of Matter

So…. either we have 1 phase or more than 1 phase First question to ask yourself: Is there one or more than one phase?

Kinds of Matter Matter One Phase Homogeneous Multiple Phases Heterogeneous

Homogeneous Matter The next question that you would ask yourself is: Can the sample of homogeneous matter be separated into parts by physical means? – Two possible answers: yes or no

Kinds of Matter Pure Substance Homogeneous Matter CAN IT BE SEPARATED? Homogeneous Mixture Yes NO

Kinds of Matter Homogeneous Mixture: A mixture that exists in one phase – Also known as a solution

Kinds of Matter Solutions – Two Parts: Solvent: Part of the mixture in greatest amount Solute: Part in lower amount – Can have more than one

Kinds of matter

Kinds of Matter

Solutions – Solutions can contain different amounts of solute per amount of solution Variable composition

Kinds of Matter Solutions: – Each part of the solution keeps its own properties – True of all types of mixtures Not just solutions

Kinds of Matter

Solutions Examples Tea Salt Water Gasoline

Kinds of Matter Solutions – Can be separated by Evaporation – Due to components maintaining their own boiling points – Example: Salt water

Kinds of Matter Evaporation is a major technique in obtaining salt.

Kinds of Matter Pure Substance Homogeneous Matter CAN IT BE SEPARATED? Homogeneous Mixture Yes NO

Kinds of Matter Pure Substances Elements Compounds

Kinds of Matter ELEMENTS – Made of one kind of particle (atom) – Cannot be broken down to something simpler

Kinds of Matter Elements Classified using the Periodic Table – Represented by Chemical Symbols

Kinds of Matter

Elements: metals

Kinds of Matter

Elements: Nonmetals

Kinds of Elements

Kinds of Matter Elements: Metalloids

Kinds of Elements

Kinds of Matter

Compounds – Pure substance composed of 2 or more elements combined in DEFINITE RATIOS

Kinds of Matter

Compounds Chemical Bond: Force of attraction that holds atoms together to make a compound – Major topic for later Molecule: Multiple atoms held together by chemical bonds. The simplest unit of a compound

–L–Law of Definite Proportions: Individual compounds are always composed of the same elements in exactly the same proportion by mass –E–Example: Water is always composed of Hydrogen and Oxygen in a 1 to 8 mass ratio

Kinds of Matter Law of Definite Proportions allows us to use chemical formulas to represent chemical compounds. The chemical formula for a compound is constant – Water is always H 2 O, Ammonia is always NH 3

Kinds of Matter Compounds: – Parts cannot be separated by physical means (filtration, evaporation…)

Kinds of Matter Compounds – When compounds are broken down it is by chemical means – Bonds break,atoms rearrange, new bonds form to give new, pure substances

Kinds of Matter

Matter One Phase Homogeneous Multiple Phases Heterogeneous

Kinds of Matter Big difference in heterogeneous mixtures and homogeneous mixture is particle size – Solutions have particle size in range of atoms and/or molecules – Heterogeneous mixture: particles greater than 1000 nm diameter

Kinds of Matter Heterogeneous Mixtures – Variable in composition – Parts of mixture can be separated by physical means Often based on particle size – filtration