matter properties and classification ap chemistry croatan high school thanks to david english
TRANSCRIPT
MatterProperties and Classification
AP ChemistryCroatan 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
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 PhaseHomogeneous
• 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 MatterCAN IT BE SEPARATED?
HomogeneousMixture
YesNO
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
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
Kinds of MatterSolutions
ExamplesTeaSalt WaterGasoline
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 MatterCAN IT BE SEPARATED?
HomogeneousMixture
YesNO
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
Kinds of Matter
• Elements: metals
Kinds of Matter
Kinds of Matter
• Elements: Nonmetals
Kinds of Elements
Kinds of Matter
• Elements: Metalloids
Kinds of Elements
Kinds of Matter
Kinds of Matter
• Compounds–Pure substance composed of 2 or more elements combined in DEFINITE RATIOS
Kinds of Matter
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
–Law of Definite Proportions:Individual compounds are always composed of the same elements in exactly the same proportion by mass–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 H2O, Ammonia is always NH3
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
Kinds of Matter
Matter
One PhaseHomogeneous
Multiple PhasesHeterogeneous
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