Chapter 1 Outline Matter, Measurement, and Problem Solving

Chapter 1 Outline – Matter, Measurement, and Problem Solving

I. Atoms and Molecules A. Atoms – submicroscopic particles that constitute the fundamental building blocks of ordinary matter B. Molecules – two or more atoms joined in a specific geometrical arrangement C. Chemistry – the science that seeks to understand the behavior of matter by studying the behavior of atoms and molecules II. The Scientific Approach to Knowledge A. Hypothesis – a tentative interpretation or explanation of the observation B. Experiments – highly controlled procedures designed to generate such observations C. Scientific Law – a brief statement that summarizes past observations and predicts future ones D. Law of Conservation of Mass – in a chemical reaction matter is neither crated nor destroyed E. Theory – one or more well-established hypotheses F. Atomic Theory – matter was composed of small indestructible particles called atoms G. Scientific Method – an approach to acquiring knowledge about the natural world that begins with observations and leads to the formation of testable hypothesis III. The Classification of Matter A. Matter – anything that occupies space and has mass B. The States of Matter – Solid, Liquid, and Gas 1. Solid matter – atoms or molecules are packed closely to each other in fixed locations 2. Crystalline – atoms or molecules are arranged in patterns with long-range repeating order 3. Amorphous – atoms or molecules do not have any long-range order 4. Liquid matter – molecules or atoms are packed about as closely as they so in solid matter but are free to move relative to each other giving liquids a fixed volume not a fixed shape 5. Gaseous matter – atoms or molecules have a lot of space between them are free to move relative to one another making gases compressible C. Classifying Matter According to its Composition – Elements, Compounds, and Mixtures 1. Pure Substance – one composed of only a single type of atom or molecule 2. Mixture – a substance composed or two or more different types of atoms or molecules 3. Element – a substance that cannot be chemically broken down into a simpler substance 4. Compound – a substance composed of two or more elements in fixed definite proportions 5. Heterogeneous Mixture – one in which the composition varies from one region to another 6. Homogeneous Mixture – one with the same composition throughout D. Separating Mixture 1. Decanting – carefully pulling off the water into another container 2. Distillation – a process in which the mixture is heated to boil off the more easily vaporized liquid 3. Filtration – in which the mixture is pored through filter paper usually held in a funnel IV. Physical and Chemical Changes and Physical and Chemical Properties A. Physical changes – changes that alter only state appearance but not composition B. Chemical Changes – alter the composition of matter C. Physical Property – one that substance displays without changing its composition D. Chemical Property – one that substance displays only by changing its composition via a chemical change V. Energy : A Fundamental Part of Physical and Chemical Change A. Energy – the capacity to do work B. Kinetic Energy – energy associated with is motion C. Potential Energy – energy associated with its position or composition D. Thermal Energy – energy associated with the temperature of an object E. Law of Conservation of Energy – observation that energy is neither created nor destroyed VI. The Units of Measurements A. Units – standard quantities used to specify measurements B. English System – consists units of inches, yards, and pounds C. Metric System – consists unites of centimeters, meters, kilograms D. International System of Units – used by scientists and based on the metric system E. The Standard Units 1. Meter = unit of length 2. Kilogram = unit of mass 3. Second = unit of time 4. Kelvin = unit of temperature F. The Meter : A Measure of Length 1. Meter is slightly longer than a yard G. The Kilogram : A Measure of Mass 1. Kilogram defined as the mass of a metal cylinder 2. Mass of an object is a measure of the quantity of mass within it while the weight of an object is a measure of the gravitation pull on the matter within it H. The Second : A Measure of Time 1. Second is most familiar SI unit I. The Kelvin : A Measure of Temperature 1. Fahrenheit scale is the most familiar way to measure temperature 2. Celsius scale is another way to measure temperature but used more by scientists 3. Kelvin Scale avoids negative temperatures by assigning 0K to the coldest temperature possible absolute zero J. Prefix Multiples 1. Change the value of the unit by powers of 10 K. Derived Units : Volume and Density 1. Derived Unit – combination of other units 2. Volume – measure of space a. Common units of volume are liter and milliliter 3. Density is the substance is the ratio of its mass to its volume 4. Intensive Property – one that is independent of the amount of the substance 5. Extensive Property – one that depends on the amount of the substance L. Calculating Density 1. d = m divided by V VII. The Reliability of a Measurement A. Scientific measurement are reported so that every digit is certain expect the last which is estimated B. Counting Significant Figures 1. Significant Figures – non-place-holding digits, those that don’t make the decimal place 2. Exact Numbers – have no uncertainty and thus do not limit the number of significant figures in any calculations C. Precision and Accuracy 1. Accuracy – refers to how close the measured value is to the actual value 2. Precision – refers to how close a series of measurements are to one another in value or how reproducible they are VIII. Solving Chemical Problems A. Converting from one Unit to Another 1. Dimensional Analysis –Using units as a guide to solving problems 2. Conversion Factor – a fractional quantity with the unites we are converting from on the bottom and the units we are converting to on top