Chemistry… The Study of MATTER

MATTER Matter is anything that has MASS OR VOLUME Mass: Amount of MATTER in an object Volume: Amount of SPACE occupied by an object

There are TWO types of Matter… PURE SUBSTANCES MIXTURES Contain one type of particle Examples: - copper - water - hydrogen gas - NaCl (sodium chloride) Contain 2 or more pure substances Examples: - salt mixed in water - granola

1. Pure Substances ELEMENTS COMPOUNDS Contain only 1 kind of particle. It’s as simple as you can get! Examples: - Zinc (Zn) - Magnesium (Mg) Contain 2 or more elements Examples: - water (hydrogen + oxygen) - copper chloride (copper + chlorine)

Element or Compound? Grab the selection of pure substances I have provided for your group… Let’s see if you can figure out if they are elements or compounds. Record an “E” (element) or “C” (compound) AND explain your reasoning. 1.Element 4.Element 2.Compound 5.Compound 3.Compound 6.Element

2. Mixtures HETEROGENOUS HOMOGENOUS Not uniform in composition Have big clumps you can see Examples: - oil with water - sulfur mixed with iron Substances are evenly mixed together Solutions such as pop or air are a great example

PROPERTIES OF MATTER Properties are how we describe something. Another term for this would be “Characteristics of Matter” Physical Properties: -State -Solubility -Melting/Boiling Point -Conductivity -Malleability -Density -Ductility

1.States of Matter There are 3 Kinds! Solids- these DON’T need to be in a special container in order to be carried. An example is rocks Liquids- these take the shape of the container they are in An example is water Gas- these take the volume and shape of the container they are in An example is oxygen

2.Melting and Boiling Point A substance’s MELTING point is when it turns from a solid to a liquid A substances BOILING point is when it turns from a liquid to a gas.

3.Malleability ** Malleable means a material can be beaten into sheets (ex. metal foil)

4.Ductility Ductile means a material can be pulled into wires (ex. copper or aluminum)

5.Solubility How well a substance will dissolve into a given amount of another substance. Example. Salt is soluble in water. This means it dissolves in water!

6.Conductivity The ability for something to conduct electricity or heat.

7.Density How heavy something is Remember the math equation for density? Density = Mass Volume Density is expressed in these units: g/cm3 or g/mL

Chemical Properties Chemical Properties describe the behaviour of a substance as it changes into a NEW substance Flammability: Rapid reaction of substance with oxygen  release ENERGY Also called burning or combustion Example… burning gas in car engines; burning paper

Corrosion: Slow reaction of metal with oxygen to form metal oxides Example… Rusting of iron into iron oxide Reactions with Acids: Reaction of some metals (often produces gases like H2 or CO2) Example… Limestone broken down by weak acid

Let’s Remind ourselves- Chemical Changes… Are irreversible (can’t “go back” to the original reactants) Produce new substances Create new properties (ex. colours, solids from 2 liquids, etc) Give off heat or light or sometimes absorb heat!

Some More info on Density Density: The amount of matter in a certain volume of a substance Density is a quantitative property We measure density using this formula: Density = Mass (measured in grams “g”) Volume (measure in mL or cm3) When you compare densities, you are comparing heaviness

Densities of Different Substances Water… 1.00 g/mL Silver… 10.5 g/cm3 Ethanol… 0.79 g/mL If you put silver in water it will sink. This is because silver is more dense than water. If you put ethanol in water it will float. This is because ethanol is less dense than water.