Unit 2 Lesson #1 Types of Matter

Matter Anything that has mass & take up space Mass = measurement of the amount of matter an object contains Chemistry = the study of matter & the changes that it undergoes

Classifying Matter Quantitative – numerical information how much, how little, how big, how small Qualitative – descriptive information condition, color, size, shape, odor, texture

Can it be physically separated? Matter Flowchart MATTER yes no Can it be physically separated? MIXTURE PURE SUBSTANCE Is the composition uniform? no yes Can it be chemically decomposed? no yes Homogeneous Mixture (solution) Heterogeneous Mixture Compound Element

Pure Substances Every sample has same: Are made of: 1. Characteristic properties 2. Composition Are made of: 1. one type of atom: element Ex: iron, gold, oxygen 2. Two or more types of atoms: compound Ex: salt, sugar, water

Which are pure substances?

Element Simplest form of matter that has its own unique set of properties Can not be separated into simpler substances by physical or chemical means Each element is made up of a single type of atom ex. hydrogen, nitrogen, lead

Compound A substance that contains 2 or more elements chemically combined in a fixed proportion (Law of Definite Proportion) Ex. 2. Properties are different than the individual elements ex. Glucose (sugar) Glucose – sweet, white solid Carbon – black, tasteless solid Oxygen – colorless, tasteless gas Hydrogen – colorless, tasteless gas

Breaking Down Compounds Physical methods do not work Recall… Chemical changes – a change that produces matter with a different composition than the original matter

Symbols & Formulas Chemical Symbol each element is represented by a one- or two-letter symbol H K Au H2O C6H12O6 Hydrogen Potassium Gold Water Glucose Trends: 1st letter = always capitalized 2nd letter (for an element) = always lowercase Subscripts = indicate the relative proportions of the elements in a compound

Mixtures 1. A combination of 2 or more types of matter 2. Each component keeps its own identity & properties 3. Components are only physically mixed & can be separated using physical means Cinnamon & Sugar Chicken noodle soup Air

Types of Mixtures 1. Heterogeneous mixture - a mixture in which the substances are not evenly distributed Oil & vinegar Salad Ice tea with ice

a mixture or ‘solution’ in which the substances are evenly distributed 2. Homogeneous mixture – a mixture or ‘solution’ in which the substances are evenly distributed Water Kool-Aid Stainless Steel

Phase – used to describe any part of a sample Phase – used to describe any part of a sample with uniform composition & properties Homogeneous mixture Heterogeneous mixture 1 phase 2 phases

Practice Examples: Type of Matter graphite pepper sugar (sucrose) paint soda Type of Matter element hetero. mixture compound solution

Separating Mixtures ‘Plays’ on differences in physical properties 1. Filtration – a technique that uses a porous barrier to separate a solid from a liquid Can you think of any common applications?

2. Distillation – a technique that can be 2. Distillation – a technique that can be used to physically separate most homogeneous mixtures based on differences in the boiling points of the substances involved

3. Chromatography – a technique that is 3. Chromatography – a technique that is used to physically separate the components of a mixture based on the tendency of each component to travel or be drawn across the surface of another material

Crystallization Separation technique that results in the formation of pure solid particles from a solution containing the dissolved substance As one substance evaporates, the dissolved substance comes out of solution and collects as crystals Produces highly pure solids Rocky candy is an example of this

Practice Examples: Answers: tea muddy water fog saltwater Italian salad dressing Answers: Solution Heterogeneous

Substances vs. Mixtures

Unit 2 Lesson #2 Properties of Matter

Properties of Matter 1. Extensive – a property that depends on the amount of matter in a sample ex. mass, volume, amount of energy 2. Intensive – a property that depends on the type (or identity) of matter in a sample ex. hardness, density, boiling point, electrical conductivity Substances – matter that has uniform & unchanging composition have identical intensive properties… Why? because every sample has the same composition

Extensive vs. Intensive Answers: intensive extensive Examples: boiling point volume mass density conductivity

3. Physical Properties – a characteristic that can be observed or measured w/out changing the identity of a substance ex. color, odor, taste, hardness, density, melting/boiling points, state of matter States of Matter – the physical forms in which all matter exists on Earth

Can you identify these 3 states? Solid def. shape & volume shape independent of container particles are packed together Liquid def. volume shape depends on container particles can move freely Gas indefinite volume & shape particles move quickly & spread apart

Chemical Properties Chemical Property describes the ability of a substance to undergo changes in identity any of the properties of matter that may only be observed and measured by performing a chemical change or chemical reaction. Ex. heat of combustion, reactivity with water, pH

Properties of Copper

Physical vs. Chemical Properties Examples: melting point flammable density magnetic tarnishes in air Answers: physical chemical

Unit 2 Lesson #3 Changes in Matter

Phase Changes All Physical Changes Evaporation = Liquid -> Gas Condensation = Melting = Freezing = Sublimation = Liquid -> Gas Gas -> Liquid Solid -> Liquid Liquid -> Solid Solid -> Gas All Physical Changes

Physical Changes Physical Change – a change that occurs in the physical appearance of a substance, but does not change its identity Ex. melting, boiling, freezing, evaporating, dissolving, condensing breaking, splitting, grinding, cutting, crushing

Chemical Changes Chemical Properties – relates to a substance’s ability to undergo changes that transform it into a different substance easiest to see when a chemical is reacting Chemical changes – a change that produces matter with a different composition than the original matter ex. burning, rotting, rusting, reacting, cooking, digestion, respiration

The process of photosynthesis is a chemical reaction in which light energy, carbon dioxide and water, are transformed to create glucose and oxygen.

The photosynthetic chemical reaction can be shown by writing out the element symbols for each compound. Reactants substances to the left of the arrow ‘ingredients’ CO2 and H2O Products substances to the right of the arrow ‘what is made’ or produced C6H12O6 and O2

Did a Chemical Reaction Occur? 1. Ammonium Chloride + Water 2. Sodium Bicarbonate + Calcium Chloride 3. Sodium Bicarbonate + Acetic Acid

Recognizing Chemical Changes How can you tell whether a chemical change has taken place? 1. Transfer of energy Energy may be given off in the form of heat or light 2. Change in color or odor Substances may ‘brown’ Indicators

3. Precipitate A solid that settles out of a liquid mixture 4. Gas production Indicated by the formation of ‘gas bubbles’

Did a Chemical Reaction Occur? 1. Ammonium Chloride + Water NH4Cl(s) + H2O(l) + Heat ----> NH4 + (aq) + Cl -(aq) + H2O(l) 2. Sodium Bicarbonate + Calcium Chloride NaHCO3(s) + CaCl2(s) ----> CaCO3(s) + NaCl(aq) + HCl (aq) 3. Sodium Bicarbonate + Acetic Acid NaHCO3(s) + CH3COOH(aq) ----> NaCH3COO-(aq) + CO 2(g) + H2O(l)

Physical vs. Chemical Changes Examples: rusting iron dissolving in water burning a log melting ice grinding spices Answers: chemical physical

Law of Conservation of Matter During any chemical reaction, the mass of the products is always equal to the mass of the reactants + O2 + CO2 + H2O vapor

I. Law of Conservation of Mass Although chemical changes occur, mass is neither created nor destroyed in a chemical reaction Mass of reactants equals mass of products massreactants = massproducts A + B  C

Conservation of mass also applies to physical changes… 10g of liquid H2O 10g of ice