1.2 Investigating Matter

Objectives By the end of the lesson you should be able to: Describe matter using physical properties Use the KMT to describe changes of state

1.2 Investigating Matter Matter is anything that has mass and volume Mass: amount of matter in a substance, often measured in grams (g) Volume: amount of space a substance or object occupies (L)

Describing Matter Physical Properties: characteristics that can be observed or measured Qualitative: described (descriptive words – think QUALity) Quantitative: measured numerically (numbers – think QUANTity)

Properties Qualitative Property Description Quantitative Property State S, L, G Colour Silver, black, red, etc Malleability Ability to be beaten into sheets Ductility Ability to be drawn into wires Crystallinity Shape or appearance of crystals Magnetism Tendency to be attracted to a magnet Properties Quantitative Property Description Solubility Ability to dissolve in water Conductivity Ability to conduct electricity or heat Viscosity Resistance to flow Density Materials mass / volume Melting/Freezing Point Temperature of melting/freezing Boiling/Condensing Point Temperature of boiling/condensing

KMT: Kinetic Molecular Theory Kinetic Energy: the energy of motion Kinetic Molecular Theory: explains what happens to matter as the energy in the particles changes

KMT 1. All matter is made up of very small particles 2. There is empty space between particles 3. Particles are constantly moving Particles of a solid are so tightly packed together that they cannot move around freely. They can only vibrate Particles of a liquid are farther apart, they can move by sliding past each other Particles of a gas are very far apart, they move around quickly 4. Energy makes particles move. The more energy particles have, the faster they can move and the farther apart they can get

Changes of State: Energy Levels and Temperature? Gas Solid Liquid Condensation Deposition Evaporation Sublimation Melting Solidification

KMT and Changes of State When you have a substance in a solid state, we say it has low kinetic energy When you have a substance in a liquid state, we say it has an increased level of kinetic energy When you have a substance in a gaseous state, we say it has high kinetic energy

KMT So when we talk about Kinetic energy, what are we specifically talking about? We are talking about the energy level in the particles that make up your substance and how fast they are moving

Types of Changes Chemical Changes A change in matter that results in a new substance HINTS: explosions, colour changes when heated Physical Changes A change that results in a change of appearance but no new substance HINTS: state changes

Types of Changes Physical Change – a change in matter in which no new substance is produced. Examples: Popping a balloon, boiling water, breaking glass Chemical Change – a change in matter in which one or more new substances are produced. Example: Rust on a car, burning a match

Chemical Change A chemical change is a change in matter that occurs when substances combine to form new substances Eg. Fireworks exploding, gases form from the solids in the fireworks

Chemical Change Designers who make fireworks know that certain substances will change color when they heated. Sparklers glow bright white because of magnesium. Magnesium is often added to these fireworks

Types of Changes Ways to Identify Chemical Changes: Hard to reverse Something new is produced Heat and light may be given off Bubbles of gas may be given off Solid materials (precipitate) may form in a liquid New colour may appear

Hard to Reverse: Rust

Something New is Produced

Heat and Light Given Off: Burning Wood

Bubbles Given Off

Solid Materials Form in a Liquid

Colour Change

Pure Substances Can be either elements or compounds Elements: cannot be broken down into simpler substances Compounds : are two or more elements combined

Element or Compound?

Your Turn! Activity Time: Describing Matter Lab!