Matter can be classified as mixtures or pure substance Chapter 7 Grade 7 Science Unit 3 Matter can be classified as mixtures or pure substance Chapter 7 1

The Story of Archimedes *Read Story 228-229

Review: Particle Theory of Matter All matter is made up of tiny particles. These particles are always moving... they have energy There are spaces among particles. There are attractive forces between the particles. The particles of one substance differ from the particles of other

Mini-Partner Activity 1 Together think of examples for each, then answer the following 2 questions. Pure Substance Mixture

1. How would you tell the difference between a pure substance and a mixture? ____________________________________________________________________________________________________________________________________________________________________________________

1. How would you tell the difference between a pure substance and a mixture? __See (the properties) if you can see the different parts, (different states, different_ colour, texture, etc). A pure substance should be the samethroughout____________

2. How would use the Particle Theory of Matter to support your answer to question #1? ____________________________________________________________________________________________________________________________________________________________________________________

2. How would use the Particle Theory of Matter to support your answer to question #1? ___A pure substance has its own kind of particle, that are different than___ other substances particles. That____ means it should have the same____ properties throughout___________

Mixtures Vs. Pure Substances How many visible Parts? Mixtures Pure Substances May have more than one visible part (not always - think salt/sugar water) Have ONLY one visible part

Mixtures Vs. Pure Substances Uniform Througout? Mixtures Pure Substances MAY appear uniform throughout. ALWAYS appear as uniform throughout

Mixtures Vs. Pure Substances Definition? Mixtures Pure Substances They are the physical combination of two or more pure substances. They contain either a single particle or two or more atoms chemically combined to form a different substance.

Mixtures Vs. Pure Substances Examples Mixtures Pure Substances •salt water, •kool-aid •chocolate chip cookie •muddy water •salad dressing •air •sugar (C12H22O11) •gold (Au), •copper (Cu) •distilled water (H2O) •carbon dioxide (CO2) •oxygen (O2)

Mixtures Vs. Pure Substances Drawing of Particles Mixtures Pure Substances *Can be this, just as long as all the particles are the same throughout

Mini-Partner Activity 2 Read pages 232, 236, and 237. Make a list of 15-20 solutions and mixtures that you encounter in a day. Put a * those that may pose a safety risk.

Soltions Vs. Mixtures! Solutions Mixtures

Practice Questions (Homework) Pg 237 Q’s 1,2 &3

Read Page 242 - Complete the Following Flow Chart

Homogeneous vs. Heterogeneous Mixtures Also called? solutions also called mechanical mixtures

Homogeneous vs. Heterogeneous Mixtures States of Matter? solid, liquid or gas can be solid,

Homogeneous vs. Heterogeneous Mixtures Particles? the particles are evenly mixed none of the original substances are visible the particles do not evenly mix

Homogeneous vs. Heterogeneous Mixtures # of visible parts? they appear to be ONE substance the different parts are visible to the eye (may need a microscope)

Homogeneous vs. Heterogeneous Mixtures How does light pass? light passes through unaffected Light will reflect Perpendicular to the direction of the beam

Homogeneous vs. Heterogeneous Mixtures Examples Kool-aide Salt water Vegetable oil Pure air Stainless steel frying pan Granola Bar Concrete Beach Salad Dressing Computer Smog-filled air

The Tyndall Effect Light can be used to distinguish between solutions and what appears to be a solution •cannot be used to distinguish between a solution and a pure liquid

The Tyndall Effect In a Solution/homogeneous: Light passes unaffected (looks at the beaker perpendicular to the direction of the beam they will NOT see it)

The Tyndall Effect In a Mechanical Mixture/heterogeneous: The light will scatter as it passes through the mixture because all particles are not dissolved (look perpendicular to direction of the beam and you WILL see it!)

List the various homogeneous and heterogeneous mixtures in your home. Partner Activity List the various homogeneous and heterogeneous mixtures in your home. Homogeneous Heterogeneous

Mini-Lab: Compare Milk, OJ and Soda - Pure or Mixture? Pg. 238-239 Are they solutions or mixtures? Homogeneous or Heterogeneous? Did the extra magnification change you mind?

Chapter Review Questions: Page. 250-251: 1, 2, 4, 6 & 8