Matter

Intro to Matter Matter and its Properties

Matter is anything that has mass and takes up space Not matter:

What is matter made of? All matter is composed of tiny particles called atoms. An atom is the smallest unit of matter that still maintains its properties. How small is an atom? Roughly 7.8 x 1019 atoms in 1 grain of sand!

Properties of Matter We can classify or sort matter based on its properties and characteristics. Physical properties are descriptive of the matter and can be observed without changing the identity. Chemical properties describe the matter’s ability to change into another substance.

Physical Properties of Matter Shape Color State (Solid, Liquid, or Gas) Boiling Point/Melting Point Texture Solubility: ability of a substance to dissolve at a given temperature Temperature Density: ratio of an object’s mass to its volume Conductivity: ability to conduct electrical current

Chemical Properties of Matter Flammability: ability to burn Reactivity: ability to form compounds with other materials Rust Tarnish Corrosion: when a material is “eaten away” by an acid

Changing Matter Physical and Chemical Changes

Changing Matter Physical Change: changes the appearance or form but not the substance itself Chemical Change: a change that results in the production of a new substance

Physical Changes Tearing Bending Crushing Changing state Dissolving

Chemical Changes Burning Rotting Rusting Cooking Tarnishing Corroding

Chemical Changes Chemical reaction is a change in matter that produces one or more new substances. Chemical changes occur when bonds (attractions that holds compounds together) break and new bonds form.

Clues to Chemical Change There are a few clues we can look for to see if a chemical change has occurred fizzing/foaming/bubbling Change in color Odor Formation of a precipitate (solid produced when two liquids are mixed) Heat or light produced

Heat Production/Loss Endothermic: energy is brought into the reaction Feels cold Exothermic: energy is released during the reaction Feels warm

Types of Matter Elements, Compounds, and Mixtures

Matter Matter can be classified by its purity. Element: pure substance made of only 1 type of atom Gold, silver, oxygen, hydrogen, etc. Compound: substance made of more than 1 type of atom chemically combined. Salt, sugar, baking soda Mixture: substances are mixed together but not chemically combined Salad, Kool-Aid, cereal

Mixtures Mixtures can be broken down into two major groups Homogeneous: uniform properties and composition Cannot see the different parts of the mixture Heterogeneous: physically unique substances with different properties Different parts of the mixture are clearly visible

Mixtures Three Types of Mixtures: Solutions Colloids Suspensions

Solution Particles are too small to be seen Same properties throughout Examples: kool-aid, salt water

2 Parts of a Solution Solvent: largest part, dissolves the solute, and can be a solid, liquid, or gas Water is the “Universal Solvent” This is because it is the most commonly used solvent Solute: smallest part, too small to be seen in solution, dissolved by the solvent

Colloids Particles are larger than those in a solution Small, undissolved particles that do not settle to the bottom Examples: fog, milk, mayonnaise Tyndall Effect: When a the particles in a colloid scatter light that is shown through it

Suspension Has the largest particles particles can easily be seen and easily separated do not have the same properties throughout Examples: sand in water, cereal, soup

Solubility

Solubility Ability of one substance to dissolve in another at a given temperature. It is expressed in terms of the amount of solute that will dissolve in a given amount of solvent to produce a saturated solution Insolubility is the inability of one substance to dissolve in another substance

Solubility Saturated Solution: solution that contains the maximum amount of dissolved solute Unsaturated solution: substance that contains less solute than a saturated solution under the same conditions Supersaturated solution: solution that contains more dissolved solute than a saturated solution under the same conditions

Factors that affect Solubility Temperature The higher the temperature, the more soluble the solute sugar in tea Pressure If the pressure of a gas solute is higher, more of the solute can be dissolved in the solvent Ex: CO2 in soda Agitation Stirring or shaking will cause the solute to dissolve more rapidly Surface Area The greater the surface area, the more rapidly the solute can dissolve Type of Material Polar and ionic compounds dissolve in water because water is polar and attracts the charges Non-polar compounds dissolve non-polar substances

Solubility Curves Solubility curves show how much solute can dissolve in a solvent at a given temperature. Above the line is supersaturated On the line is saturated Below the line is unsaturated

Solubility Curve Practice What is the solubility of KNO3 at 55OC? A solution is prepared by adding 50 grams of KNO3 to 100 ml of water at 50OC. Is this solution saturated, unsaturated supersaturated? A solution is prepared by adding 50 grams of KNO3 to 100 ml of water at 30OC. Is this solution saturated, unsaturated, or supersaturated?