Matter. Pure Substance: Substance made up of only one kind of matter (particle).

Transcription

1 Classifying Matter

2 Matter Pure Substance: Substance made up of only one kind of matter (particle). Element: Contains only one kind of atom. The chemical symbol has one capital letter. Ex: Na Compound: A pure substance that is made of 2 or more different elements that are combined together chemically. The chemical symbol has 2 or more capital letter. Ex: NaCl

3 Example of an Element: Oxygen (O) Oxygen

4 Example of an Element: Hydrogen (H) Hydrogen

5 Example of a compound? Here you have a mixture of hydrogen and oxygen. They are not chemically combined (joined) to each other though. Not a compound. Oxygen Hydrogen Hydrogen Oxygen Oxygen Hydrogen Hydrogen

6 Example of a compound? Water is now a new substance. It is has different properties than oxygen and hydrogen. Oxygen Chemically combined Hydrogen Hydrogen Water: H 2 O. Why is this a compound but not what was on the previous slide? Because the elements on the previous slide were not chemically combined.

7 Classifying Matter

8 Mixture: A combination of pure substances (elements/compounds) that are NOT chemically combined (more than one type of particle). Homogeneous (Homo = same): The different substances that make up the mixture are not individually visible. Also called a Solution. Heterogeneous (Hetero = different): The different substances that make up the mixture are visible. Also called mechanical mixture.

9 Dissolving Sugar in coffee is an example of a solution because: 1) You cannot tell the sugar apart from the coffee (HOMOgeneous). 2) It is a mixture of two substances that are not chemically combined (coffee remains coffee and sugar remains sugar).

10 Classifying Matter

11 A salad is an example of a Mechanical heterogeneous mixture because: 1) All the different substances that make up the salad are visible (HETEROgeneous). 2) It is a mixture of two or more substances that are not chemically combined (Lettuce remains lettuce, tomato remains tomato).

12 Heterogeneous: A type called Suspension A suspensionis a cloudy mixture in which clumps of a solid or droplets of a liquid are scattered throughout a liquid or gas. Muddy water, tomato juice, and orange juice with pulp are suspensions. The parts of a suspension may separate into layersif the suspension is not stirred.

13 Fresh Milk from the cow is a suspension Farm-fresh milk is a suspension. If the milk is left standing, the fatty part (the cream) floats to the top and the watery part sinks to the bottom.

14 What about commercial milk? Commercially available milk does not separate. It is a special kind of suspension, called an emulsion, which has been treated to keep it from separating. In a process called homogenization, the milk is sprayed through very small openings. This breaks down the fat into droplets that are so tiny they stay suspended and NOT separate.

15 Classify the following as heterogeneous (suspension, mechanical) or homogeneous (solution) Brass is made of copper and zinc. They are not chemically combined. Brass is a compound/mixture. Brass is a homogeneous mixture (solution)/ Heterogeneous mixture. A mixture of solids is called an ALLOY

16 Classify the following as heterogeneous (suspension, mechanical), homogeneous (solution), or pure substance

17 Classify the following as heterogeneous (suspension, mechanical), homogeneous (solution), or pure substance

18 Classify the following as heterogeneous (suspension, mechanical), homogeneous (solution), or pure substance Cu

19 Classify the following as heterogeneous (suspension, mechanical), homogeneous (solution), or pure substance

20 Classify the following as heterogeneous (suspension, mechanical), homogeneous (solution), or pure substance

21 Classify the following as heterogeneous (suspension, mechanical), homogeneous (solution), or pure substance NaCl

22 Ca CaCl 2 H 2 O Na O 2 Cl 2 NaCl Element Compound

23 Classifying Matter