Properties of Matter

1. Properties of Matter

2. Properties of Matter Physical properties - properties that can be observed without changing the chemical makeup of the substance - mass, volume, color, shape, size, conductivity, solubility, density boiling point, melting point, viscosity

3. Physical Changes • Physical change – a change that affects only the physical properties of matter

4. Using Physical Properties and Changes to Separate • Mixtures can be separated using physical properties and changes • Distillation – process for separating a mixture by evaporating a liquid and then condensing the vapor

5. Physical Properties: Conductivity • Refers to the ability of a metal or alloy to allow heat or electricity to pass through easily. • Good conductors: • Gold & silver, aluminum, copper • Bad conductors: • Wood, glass & plastic, rubber

6. Physical Properties: Solubility • Refers to the amount of a solute (or a particle) that can be dissolved in a given solvent. • Solubility is affected by several factors.

7. Factors that Increase the Rate of Dissolving 1.) Stirring the solution (agitation) - agitating the solution increases collisions between solute and solvent particles

8. 2.) heating the solvent - speeds up the solvent particles so there are more frequent collisions between solvent and solute 3.) smaller particle size - increases surface area so there are more places the solvent can get to the solute & less bonds for solvent to break

9. Physical Properties: Density • Density is a ratio. • Refers to a specific material’s ratio of mass:volume, and can be calculated with the following equation: mass m density ________ __ = = D v volume

10. Physical Properties: Viscosity • A fluid’s tendency to resist flow. • High viscosity flows slowly, while low viscosity flows quickly.

11. Physical Properties: Melting Point • Defined as the temperature at which a solid begins to liquefy. • Particles are in an ordered arrangement (solid) and begin to slip out of this order (become a liquid). • *Can change/vary!*

12. Physical Properties: Boiling Point • Defined as the temperature at which the pressure of the vapor in the liquid is equal to the external pressure acting on the surface of the liquid. • Particles move from a liquid to a gas. • *Can be changed/varied!*

13. Chemical Properties and Changes Chemical Properties - properties that can only be observed by changing the chemical makeup of the substance - combustibility - reacts with an acid/base - capacity to corrode/oxidize

14. Signs that a Chemical Change has occurred... 1.) Gas is given off 2.) Sudden formation of a solid (precipitate) 3.) Releasing or absorbing heat 4.) Release of light 5.) Sudden color change

15. Chemical Properties: Combustibility • Defined as a substance that is able to react with oxygen to produce heat and light. • Commonly includes hydrocarbons (wood, paper, fossil fuels). • Typical combustion reaction:

16. Chemical Properties: Corrosion/Oxidation • During corrosion, metals react with oxygen, gaining electrons. • The result are oxides, new chemicals which form from a combination with oxygen. • Example: rust. • Rust is an example of oxidation, which is simply the ability of a chemical steal electrons from another chemical.

17. Law of Conservation of Mass • Law of Conservation of Mass – matter is neither created nor destroyed during a chemical change • Mass of the reactants = mass of the products