Unit 1 Matter and Measure

Measure

Scientific Measurement Two main systems US Customary Based on arbitrary measurements that have lasted through history Conversions are harder to remember Metric Based on powers of ten Prefixes determine magnitude of power of ten

International System (SI) Scientific Community has accepted certain units as base units Dimension Unit Symbol Length Meter m Mass Gram g Time Second s Temperature Kelvin K Amount Mole mol

Metric System Prefixes Power Symbol Giga 109 G Mega 106 M kilo 103 k deci 10-1 d centi 10-2 c milli 10-3 m micro 10-6 μ nano 10-9 n pico 10-12 p

Measuring Digital Displays are recorded as is Digital Mass Balance, pH meter Visually Read Scales can always be estimated to smaller increment than marked Rulers, Thermometers, Graduated Cylinders Meter stick Example

Example Length=?? 0.3m 0.31m 0.314m 0m 0.1m 0.2m 0.3m 0.4m

Percent Error

Temperature Measure related to the heat of an object Measured in °Celsius or Kelvin(no degrees) Conversion

Density Amount of matter in a given amount of space Amount of mass in a given volume

Matter

Chemistry What is Chemistry? Branches Study of matter and the changes it undergoes Branches Organic Physical Analytical Biochemical Inorganic

IUPAC International Union of Pure and Applied Chemistry Group that names elements and compounds Meets every few years

Matter Anything that has mass and takes up space, volume Classified into two categories Substances (Pure) Mixtures

Atom Simplest form of matter Made up of Subatomic Particles Different atoms have different properties

Pure Substances Element simplest form of matter that has a unique set of properties. arranged into a table, called the periodic table Can’t be broken down by chemical means denoted using chemical symbols, O, Cu, Fe Symbols always have the first letter capitalized If needed, any additional letters are not capitalized

Pure Substances (Cont) Compounds substance of two or more elements chemically combined in a fixed proportion Ex. H2O, C6H12O6 Can be broken down by chemical means

Mixtures Physical blend of two or more substances Two Types: Homogeneous Heterogeneous

Mixtures (cont) Homogeneous Heterogeneous Composition is uniform throughout Examples: Air, Olive Oil, Stainless Steel Solution is a homogeneous mixture Aqueous Solution is something mixed in water Heterogeneous Composition is not uniform throughout Examples: Salad Dressing, Chicken Noodle Soup

Separating Mixtures Differences in physical properties can be used to separate mixtures Filtration – Separates solids from liquids in heterogeneous mixtures Distillation – Separates homogeneous liquid mixtures based on different boiling points

Separating Mixtures Evaporation – evaporate away liquid to leave solid Chromatography – separation of substances based on polarity

Phases(States) of Matter Solid Definite shape and volume Particles are packed tightly together in a regular geometric pattern (s) used after chemical formulas Cu(s)

Phases of Matter Liquid Definite volume, takes shape of container Particles can slide past each other (l) used after chemical formulas H2O(l)

Phases of Matter Gas Takes shape and volume of container Particles are spread very far apart (g) used after chemical formulas H2O(g)

Aqueous Solutions Dissolved in water (aq) used after chemical symbols NaCl(aq)

Phase Changes Solid  Liquid Melting Liquid  Solid Freezing Liquid  Gas Vaporization Gas  Liquid Condensation Solid  Gas Sublimation Gas  Solid Deposition Temperature does NOT change during a phase change

Identifying Substances Physical Property quality or condition of a substance that can be observed or measured without changing the substance’s composition Ex: Color, shape, size, mass Physical Change some properties change, but the composition remains the same Can be reversible or irreversible Ex: melting, freezing, tearing

Identifying Substances (cont) Chemical Change change that produces matter with a different composition than the original matter Ex. burning, rusting, decomposing, exploding, corroding Chemical property property that can only be observed by changing the composition of the substance. Ex: Reactivity with acids, reactivity with oxygen

Chemical Changes Indications of a chemical change Transfer of Energy Change in temperature Production of Light Formation of a gas Formation of a precipitate Change in color

Physical or Chemical ? Boiling Point Physical Green color Physical Shiny Physical Conductivity Physical Solubility Physical Reacts with acid Chemical Reacts with O2 Chemical

Energy Capacity to do work Ability to do something Types: Chemical Electrical Mechanical Potential Kinetic

Energy Exchanges Exothermic Endothermic Process when energy is released or given off Ex: Burning, freezing Endothermic Process when energy is absorbed or taken in Ex: Melting

Scientific Method Observation Hypothesis Experiment using five senses to make observations. Hypothesis proposed explanation for an observation. Experiment procedure used to test a hypothesis.

Scientific Method (cont) Analyze Data check to see if results support hypothesis. Theory well tested explanation for a broad set of observations. Law concise statement that summarizes the results of many observations and experiments.

Scientific Laws Law of Conservation of Mass Mass can not be created or destroyed, only changed into different forms Law of Conservation of Energy Energy can not be created or destroyed, only changed into different forms