Test Review Answers

Question 1 1a)Heterogeneous (“different kinds”) A mechanical mixture. 2 or more substances can be seen or felt. Homogeneous (“same kind”) A solution Particles of 2 or more pure substances mix completely Feel and look like one substance Properties of sample always the same

Colloids b) A mixture in which extremely small particles are evenly distributed and are hard to see with the unaided eye. Example: whipped cream, fog Suspensions a mixture where the particles, if left alone, gravity will help separate. Example: Italian salad dressing Ketchup

Classification of Matter Mixture – Two or more pure substances mixed together. A special type of mixture is an alloy. See below. Even though it may look different, it is still copper and zinc. Each metal retains its own properties like melting point. Example: Copper and Zinc can be mixed together to produce brass.

Pure Substances Examples:Carbon Dioxide (CO2) Water (H2O) Pure substances can also be divided into 2 categories: compounds and elements. Compound – Two or more elements chemically bonded together. Examples:Carbon Dioxide (CO2) Water (H2O) Salt (NaCl) Sucrose (C12H22O11) Elements – Substances made up of only one type of atom. - Cannot be separated by any physical OR chemical process.Examples:Carbon, Helium,Gold

Mechanical Mixture Solutions a substance made of more than one kind of particle in which the particles are not uniformly scattered. (heterogeneous) example: pizza Solutions A homogeneous mixture of 2 or more pure substances. Ex. Kool-Aid

Weight is the measure of gravitational pull on matter, measured in Newtons. Weight can vary depending on where you are. Mass is the amount of matter in an object measured in grams using a balance scale.

A physical property describes the qualities of matter that will not change its composition. Examples:color,malleability,ductile, shape A chemical property describes the qualities of matter that will change its composition. Examples: combustibility, flammability, corrosive.

Question 3 a) physical b) physical c) chemical d) chemical

Question 4 Three indicators of a chemical change are: 1. Gas is produced (bubbles, fizz) 2. Color change (cooking) 3. Burning, fire, explosives 4. Rust

Question 5 a) chemical b) physical c) physical d) chemical e) physical f) chemical

Question 6 a) Mechanical Mixture b) element (on periodic table) c) Suspension (need to shake) d) solution e) colloid (white, cloudy) f) mechanical mixture g) element h) colloid I) alloy (solution of metals) j) mecanical mixture j) element k) suspension (settle over time)

The Particle Theory All matter is composed of tiny particles. Size and shape vary. All particles of pure substance are exactly the same size. All particles of one substance are the same Salt particles are different from pepper particles

The Particle Theory There are spaces between particles. Particles are always moving – the more energy they have, the faster they move.  temp the faster the particles move There are forces of attraction between particles.

M2ASS The Particle Theory Matter has particles Moving particles Energy is transferred between particles by moving particles hitting each other and either speeding up or slowing down. Matter has particles Moving particles Attraction between particles Same particles throughout Spaces between particles M2ASS

Matter Solid Particles are close together and locked together into a pattern. Attractive forces are very strong. Particles move, but only vibrate in one place.

Matter Liquid Particles are slightly farther apart Attractive forces are weaker Particles are able to slide past one another

Matter Gas Particles are far apart. Attractive forces are weakest. Particles are able to move in any direction.

Classification of Matter Any substance or material that has mass and occupies space. matter mixtures pure substances mechanical mixture (heterogeneous) solutions (homogeneous) Matter can exist in 4 states: solid, liquid, gas and plasma

Law of Conservation of Matter No matter can be created or destroyed. In a chemical reaction, the mass of the reactants will always equal the mass of the products. As well, the individual atoms will not be lost. If we start with 4 atoms of Carbon, we will end with 4 atoms of Carbon, however in different forms of matter. Example: water + baking soda