Matter Matter: Physical & Chemical Properties & Changes

Matter is composed of two broad categories: Matter is composed of two broad categories: A. MIXTURES & B. PURE SUBSTANCES

A.) MIXTURES  composed of two or more substances and can be separated through physical means. Ex: sulfur & iron filings, NaCl & H 2 O, Kool-Aid, muddy water, a bin of recyclable materials, whipped cream Ex: sulfur & iron filings, NaCl & H 2 O, Kool-Aid, muddy water, a bin of recyclable materials, whipped cream Separation methods include – sifting, separating using hands or specialized equipment, distilling, heating, filtering, cooling etc.

Types of Mixtures 1. Heterogeneous –(different)- the two or more parts of the mixture can visibly be distinguished. Special Type of Heterogeneous Mixture: Suspension – Heterogeneous fluid containing solid particles that are sufficiently large for sedimentation. Suspension – Heterogeneous fluid containing solid particles that are sufficiently large for sedimentation. Examples of SUSPENSIONS: Muddy water, oil & vinegar dressing, Milk of Magnesia, toothpaste

2. Homogeneous – (same) Homogeneous Mixtures – cannot visibly distinguish the two or more parts of the mixture. SOLUTIONS a uniform mixture consisting of only one phase. Examples of SOLUTIONS : Saline solution (salt water), tears, coffee, blood, Kool-aid, Windex, air with no clouds, syrup, iced/hot tea etc. COLLOIDS –Homogeneous solution with intermediate particle size between a solution and a suspension. Colloid particles may be seen in a beam of light such as dust in air in a "shaft" of sunlight. Examples of COLLOIDS: Milk, Mayonnaise, Fog, Jell-O, Smoke, Whipped Cream and Shaving Cream

B.) PURE SUBSTANCES – are composed of one or more atoms and cannot be separated through physical means.are composed of one or more atoms and cannot be separated through physical means. Ex: sulfur, iron, NaCl, C 6 H 12 O 6 (glucose), H 2 O, CO 2 Ex: sulfur, iron, NaCl, C 6 H 12 O 6 (glucose), H 2 O, CO 2

Types of Pure SUBSTANCES : 1.) COMPOUNDS or MOLECULES – (atoms are different) Sodium Chloride, Glucose, or Water 2.) ELEMENTS – (atoms are the same) Sulfur, Gold, Silver, Mercury, Tin, Hydrogen, Oxygen

PHYSICAL AND CHEMICAL PROPERTIES Properties help us to identify substances & characteristics

PHYSICAL PROPERTIES – Quality or condition of a substance that can be observed or measured without changing the substance’s composition. – Quality or condition of a substance that can be observed or measured without changing the substance’s composition.

The Elements on the Periodic Table can be broken down into three basic categories… Metals Non-Metals Metalloids Let’s examine their physical properties…

Periodic Table of the ELEMENTS Metals – light blue Nonmetals – dark blue Metalloids

Properties of Metals 1.luster (shininess) 2.good conductors of heat and electricity 3.high melting points 4.ductile (capable of being drawn into thin wires) 5.malleable (most metals can be hammered into thin sheets)

Properties of Nonmetals 1.dull appearance (not shiny) 2.poor conductor of heat & electricity (insulators) 3.brittle (breaks easily) 4.low density 5.low melting points 6.not ductile and not malleable.

Found along the “stair step line” of the Periodic Table Metalloids include: boron, silicon, germanium, arsenic, antimony, tellurium, polonium, and astatine Aluminum is NOT a metalloid—it is a metal Metalloids

Metalloids 1. Solids 2. Can be shiny or dull 3. Semi-ductile 4. Semi-malleable 5. Semi-Conductors of heat and electricity.

EXTENSIVE PROPERTY Depends on the amount of matter. Example – Length, mass, volume, weight INTENSIVE PROPERTY – Does not depend on the amount of matter. Example – Color, density, hardness, ductility, malleability, odor, melting point Additional Physical Properties…

The ability of a substance to undergo chemical reactions and form NEW substances Chemical Properties describe CHEMICAL CHANGES CHEMICAL PROPERTIES

Nonmetals – tend to gain (e-)(since metals tend to lose (e-)and nonmetals tend to gain (e-), metals and nonmetals like to form compounds with each other. Nonmetals – tend to gain (e-) (since metals tend to lose (e-) and nonmetals tend to gain (e-), metals and nonmetals like to form compounds with each other. These compounds are called ionic compounds. When two or more nonmetals bond with each other, they form a covalent compound. Metals – easily lose (e-), corrode easily (corrosion is a gradual wearing away). Example: silver tarnishing and iron rusting.

PHYSICAL & CHEMICAL CHANGES

PHYSICAL CHANGES alter a substance without changing its composition. Examples – cut, grind, boil, freeze, melt, condense, break, separate,chop, split, mix, tear, crush and blend.

Let’s illustrate this… Ex.3: Refining crude oil--separates oil into it’s component parts. Ex. 1: When water boils, it changes state (liquid to gas). This is a physical change. The water is still composed of H 2 O regardless of the state of matter it is in. Ex. 2: Fractional distillation is a process of separation based on boiling points.

CHEMICAL CHANGES A substance or substances are changed into NEW substances.

1.) A gas is produced (bubbles) Ex: 2 HCl + Fe  FeCl 2 + H 2 Ex: 2 HCl + Fe  FeCl 2 + H 2 OR Alka seltzer + H 2 O  CO 2 OR Alka seltzer + H 2 O  CO 2 Evidence of Chemical Change 2.)HEAT is produced 2.)HEAT is produced Ex: Paper burning OR EXOthermic RXN Ex: Paper burning OR EXOthermic RXN

3.) Light is given off… EX. Magnesium (Mg) burning 3.) Light is given off… EX. Magnesium (Mg) burning 4.) Color change 5.) Odor produced 6.) Formation of a precipitate (solid) 6.) Formation of a precipitate (solid)