Section 1 * Lab * 2 wksts * Quiz Pure substance Only one type of particle Called Atoms Metals Nonmetals Elements Categories Boiling Point Help you identify a specific element Melting Point Characteristic Properties Density Chemical Properties EX: reactivity with acid Metalloids Element a substance that cannot be separated or broken down into simpler substances by chemical means. Pure Substance a sample of matter, either a single element or a single compound, that has definite chemical and physical properties. Metal an element that is shiny and that conducts heat and electricity well. Nonmetal an element that conducts heat and electricity poorly. Metalloid an element that has properties of both metals and nonmetals.
Section 2 * Lab * Quiz Pure substance Made of elements Chemically combined Elements join in specific ratios EX: Mass of Hydrogen to the mass of Oxygen in water is 1 to 8 or 1:8 Compounds Physical Properties Chemical Used to identify compounds Use chemical change to break down to elements or simpler compounds Add energy by heat or electricity Ex: Sodium reacts violently with water. Chlorine is a poisonous gas. Combined they make sodium chloride (table salt) Found everywhere Food Clothing Proteins Aluminum oxide Ammonia Carbon dioxide carbohydrates Compound a substance made up of atoms of two or more different elements joined by chemical bonds.
Section 2 Familiar Compounds Compound Table Salt Water Vinegar Carbon Dioxide Baking Soda Elements combined Sodium and Chlorine Hydrogen and Oxygen Hydrogen, Carbon, and Oxygen Carbon and Oxygen Sodium, Hydrogen, Carbon, and Oxygen
* 4 worksheets * Lab * Test Properties Mixtures Solutions No chemical changes happens Some are easy to separate, some are hard No specific ratio Ex: Pizza toppings, salt water Particles are large enough to settle and scatter/block light Suspensions Ex: Snow Globes Salad dressing Can be separated by filtering Colloids Can t be separated by filtering doesn t settle out Ex: Milk, Mayo, Gelatin, Whipped cream Particles are smaller than in a suspension Mixture a combination of two or more substances that are not chemically combined. Suspension a mixture in which particles of a material are more or less evenly dispersed throughout a liquid or gas. Colloids a mixture consisting of tiny particles that are intermediate in size between those in solutions and those in suspensions and that are suspended in a liquid, solid or gas.
Mixtures and Compounds Mixtures Compounds Made of elements, compounds, or both No change in original properties of components Separated by physical means Formed using any ratio of components Made of elements Change in original properties of components Separated by chemical means Formed using a set ratio of components
* Appears to be a single substance. * Particles don t settle very small * Doesn t scatter light. Solutions Alloys: solid solutions metal & metal or nonmetal & nonmetal Substance in which another substance is dissolved or the larger amount of liquid or gas: Solvent Substances that dissolve: Solute Ex: salt water Substances must be soluble to create a solution. Solution a homogeneous mixture of two or more substances uniformly dispersed throughout a single phase Solvent in a solution, the substance in which the solute dissolves. Solute in a solution, the substance that dissolves in the solvent. Soluble able to dissolve Insoluble unable to dissolve
Examples of Different States of Solutions States Gas in gas Gas in liquid Liquid in liquid Solid in liquid Solid in solid Examples Dry air (oxygen in nitrogen) Soft drinks (carbon dioxide in water) Antifreeze (alcohol in water) Salt water (salt in water) Brass (zinc in copper)
Concentrations of Solutions Expressed in grams of solute per milliliter of solvent Dilute either Concentrated Does not tell the amount of solute dissolved Concentration the amount of a particular substance in a given quantity of a mixture, solution, or ore. Dilute a solution with less solute. Solubility Ex: just the right amount of sugar can be completely dissolved in water Concentrated a solution with more solute. Ex. Soft Drinks go flat faster when they are warm. Dissolving Gases in Liquids Less soluble as temperature is raised Solubility the ability of one substance to dissolve in another at a given temperature or pressure. Dissolving Solids faster in Liquids Mixing Crushing Heating