Presentation is loading. Please wait.

Presentation is loading. Please wait.

Chemical and physical change. PHYSICAL PROPERTIES OF MATTER.

Similar presentations

Presentation on theme: "Chemical and physical change. PHYSICAL PROPERTIES OF MATTER."— Presentation transcript:

1 Chemical and physical change


3 What are Properties used to describe parts of the car?

4 Some Physical Properties HardnessOdor ColorTexture DensityState of matter Strength Flexibility (malleable, ductile) Shape Melting point, boiling point Ability of conduct electricity

5 What is a physical property? Any characteristic that can be used to describe matter Often very easy to observe

6 Melting/Boiling/Freezing points The temperatures when an object changes it’s state of matter

7 Definitions of Melting, Boiling, Freezing points Boiling point: the temperature at which a liquid becomes a gas, or vice versa Melting point: the temperature at which a solid becomes a liquid Freezing point: same as melting point, but used when the temperature is cooling (decreasing)

8 Instances, examples What is freezing point of water? What is the boiling point of water?

9 The numbers Freezing point: 32°F or 0°C Melting point: 212°F or 100°C How to convert Fahrenheit to Celsius: C=5(F-32)/9 1.Begin by subtracting 32 from the Fahrenheit number. 2.Divide the answer by 9. 3.Then multiply that answer by 5. Here's an example: Change 95 degrees Fahrenheit to Celsius: 95 minus 32 is 63. Then, 63 divided by 9 is 7. Finally, 7 times 5 is 35 degrees Celsius.


11 Possible evidence of physical change Alteration of any physical feature – Length – Shape – Color Application of force which changes the object – Pounding – Tumbling – stretching

12 Changes in matter Physical Change 1.Does not change a substance identity (chemical makeup, formula) 2.Does change at least one physical property 3.Dissolving is a physical change 4.Changing the state of matter is a physical change 5.Separation of a mixture into its ingredients is a physical change

13 Examples of physical changes in matter Hair Cut Breaking Chalk Crushing an aluminum can

14 Dissolving is a physical change


16 What chemical changes have occurred?

17 Definition of chemical property A property of matter that describes the substance’s ability to participate in chemical reactions A chemical property describes how a substance interacts with the materials in the surrounding environment to form new compounds or elements.

18 Examples of Chemical properties Reactivity Sulfuric acid and Sugar Flammability Carbon Compounds in wood, oxygen in the air and an igniter

19 Sulfuric Acid and Reactivity Demo

20 REACTIVITY Chemical Property

21 Reactivity The ability of a substance to combine chemically with another substance and form new or different compounds

22 FLAMMABILITY Chemical Property

23 Flammability The ability of a substance to react in the presence of oxygen and burn when exposed to heat energy


25 Chemical change Occurs when 1 or more substances react to form new substances with different properties Chemical Properties can only be detected when a change occurs Chemical changes can be detected Chemical changes cannot be reversed by physical changes Compounds can be broken down through chemical changes

26 Possible evidence of chemical change… Change in texture Change in smell Something bubbles or fizzes Changing color

27 Chemical change CO 2 Gas made by combining Sodium Bicarbonate (NaHCO 3 ) and water (H 2 O)

28 Results when combining baking soda and with vinegar Vinegar and baking soda chemically react, creating new compounds: CO 2 (g) + NaC 2 H 3 O 2 (aq) (sodium acetate)

29 Chemical reactions Magnesium reaction with water

30 Chemical reaction between sodium and water

31 Important Note The ability not to react with other substance or not burn is also a chemical property


33 Elements with non reactive properties Gold Argon Gas in Light Bulb

34 Galvanized steel is steel coated with zinc Not galvanized Galvanized nails

35 Another use for non-reactive materials Dentures, False Teeth, Replacement teeth made from acrylic plastic. Nontoxic, hard, water proof, unreactive, and affordable

36 Comparing Physical and Chemical properties 1.You can observe physical properties with no visual change substance (the car is red) 2.Observation of chemical properties only occurs when the substance changes (the car is rusting) 3.A physical change in a material does NOT require a change to its chemical identity. A chemical change does

37 List a Physical and Chemical property of various materials below: SubstancePhysical PChemical P Helium Wood Baking Soda Powdered Sugar Iron Water


39 Characteristic properties Most useful in identifying and classifying substances Can be both physical and chemical Examples are a substance’s density, melting point, solubility, and reactivity


41 How chemical reactions can be used to determine identity of substance Both baking soda and powdered sugar are white powders Baking soda reacts with vinegar Sugar does not

Download ppt "Chemical and physical change. PHYSICAL PROPERTIES OF MATTER."

Similar presentations

Ads by Google