# Unit 1

# Unit 2

# Physical Properties
- A characeristic of a substance that can be determined without changing the composition ("make-up") of that substance
- Characteristics can be determinded using your 5 senses and measuring instruments 
  - smell, taste, touch, hearing, sight
  - scales, tape, measuring meter
  
# Qualitative and Quantitative Properties

> |Type|Definition|Example|
> |:---|:---------|:------|
> |Quantitative Property|A property that IS measured and has **```a numerical value```** |Ex. **```Temperature, height, mass, density```**|
> |Qualitative Property|A property that is NOT measured and has **```no numerical value```**|Ex. **```Colour, odor, texture```**|

> ## Quantitative physical Properties
> - **```Density```**: amount of ```stuff``` (or mass) per unit volume (g/cm<sup>3</sup>)
> - **```Freezing Point```**: point where water solidifies (0<sup>o</sup>C)
> - **```Melting Point```**: point where water liquefies (0<sup>o</sup>C)
> - **```Boiling Point```**: point where liquid phase becomes gaseous (100<sup>o</sup>C)

>> ## Common Qualitative Physical Properties

>> |Type|Definition|Example|
>> |:---|:---------|:------|
>> |Lustre|Shininess of dullness<br> Referred to as high or low lustre depending on the shininess||
>> |Clarity|The ability to allow light through|```Transparent``` (Glass) <br>```Translucent``` (Frosted Glass) <br>```Opaque``` (Brick)|
>> |Brittleness|Breakability or flexibility<br> Glass would be considered as brittle whereas slime/clay are flexible|
>> |Viscosity|The ability of a liquid or gas to resist flow or not pour readily through<br> Refer to as more or less viscous|Molasses is more viscous, water is less (gases tend to get"thicker as heated; liquids get runnier)|
>> |Hardness|The relative ability to scratch or be scratched by another substance<br> Referred to as high or low level of hardness| Can use a scale (1 is wax, 10 is diamond)|
>> |Malleability|the ability of a substance ```to be hammered``` into a thinner sheet or molded|Silver is malleable<br> Play dough/pizza dough is less<br> glass is not malleable|
>> |Ductility|the ability of a substance to be pulled into a finer strand|Pieces of copper can be drawn into thin wires, ductile|
>> |Electrical Conductivity|The ability of a substance to allow electric current to pass through it<br> Refer to as high and low conductivity|Copper wires have high conductivity<br> Plastic has no conductivity|
>> |Form: Crystalline Solid|Have their particles arranged in an orderly geometric pattern|Salt and Diamonods|
>> |Form: Amorphous Solid|Have their particles randomly distributed without any long-range-pattern|Plastic, Glass, Charcoal|

# Chemical Property

> A characteristic (property) of a substance that describes its ability to undergo ```changes to its composition to produce one of more new substances. AKA BEHAVIOUR. Everything has one!```
> ```Cannot be determined by physical properties```

> E.g. ability of nails /cars to rust
> Firewors are explosive

> Denim is resistant to soap, but is combustible

> Baking soda reacts with vinegar and cake ingredients to rise

> Bacterial cultures convert milk to cheese, grapes to wine, cocoa to chocolate

> CLR used to clean kettles, showerheads because it breaks down minerals

> Silver cleaner for tarnished jewellery, dishes because silver reacts with air to turn black


# Elements

- At the present time ```118``` elements are known.
- These elements vary widely in their abundance
- For example, only five elements account for over 90% of the Earth's crust: oxygen, silicon, aluminum, iron and calcium.


 
  
  
  
