Presentation on theme: "What’s the MATTER, part II. Types of Matter Pure Substance- Matter with a fixed composition It has distinct properties Examples =elements compounds."— Presentation transcript:
Types of Matter Pure Substance- Matter with a fixed composition It has distinct properties Examples =elements compounds
Pure substance = Only ONE element or compound (distilled water). Pure substance = Only ONE element or compound (distilled water). Some Examples:
Mixtures- Most matter is a mixture The composition is not fixed (changes from sample to sample) Two Types – Homogeneous Heterogeneous
Some Examples: Mixtures are variable combinations of 2 or more pure substances. Heterogeneous – visibly separate phases Homogeneous – Same throughout
Air is a mixture of several gases. Name Formula amount Nitrogen N 2 78 % Oxygen O 2 21 % Argon Ar 1 % Carbon CO 2 0.03 % Dioxide
Homogeneous Mixtures Composition is uniform throughout Solution- Particle size = 0.01 – 1 nm Doesn’t settle out upon standing Can’t be separated by filtering Doesn’t scatter light Example = distilled water
Colloid- Particle size = 1 – 1000 nm Doesn’t settle out upon standing Can’t be separated by filtering Scatters light (Tyndall Effect) Examples = milk, gelatin, smoke
Heterogeneous Mixtures The sample varies in composition, properties and appearance No uniformity Particle size is greater than 1000 nm Particles settle out upon standing Can be separated by filtration Might scatter light Examples = soil, trail mix, pond water
Physical vs. Chemical Properties Every substance has a unique set of properties (characteristics that identify that substance) Physical Properties- Properties that can be measured without changing the identity and composition of the substance
Physical Property Examples- Color Odor Density Melting Point Boiling Point Hardness Solubility
Physical Change A change in matter from one form to another without changing its chemical properties (most can be reversed) Examples = Change in state Dissolving Compressing
Chemical Properties Properties that describe the way a substance may change to form other substances Only observed when a chemical reaction takes place
Chemical Property Examples Heating to combustion Reactivity with water or acid Flammability Corrosion Decomposition
Law of Conservation of Mass In a physical change or a chemical reaction, mass is neither created or destroyed (Antoine Lavoisier)
Is the composition uniform? NoYes MATTER Can it be physically separated? Homo- geneous Mixture (solution) Hetero- geneous Mixture Compound MIXTURE PURE SUBSTANCE Yes No Can it be chemically decomposed? No Yes Suspensions Element Colloids
Putting sand and salt together makes a compound. an element. a mixture. a solution.
Pure Water is a compound. an element. a solution. a mixture. Pure Water is a compound. an element. a solution. a mixture.
Tap Water is a compound. an element. a solution. a mixture. Tap Water is a compound. an element. a solution. a mixture.
Salt (NaCl) is a common substance. Salt is which of these? atom element compound mixture Salt (NaCl) is a common substance. Salt is which of these? atom element compound mixture
Which formulas represent compounds? O 2, H 2 O 2 CO 2, H 2 O H 2, CO 2 H 2, O 2 Which formulas represent compounds? O 2, H 2 O 2 CO 2, H 2 O H 2, CO 2 H 2, O 2
Which of the following is a compound? oxygen water nitrogen air