Chapter 1 Outline Quantitative vs Qualitative Hypotheses Theories and Laws Data Ideas in Science Matter Mixtures Homogeneous Heterogeneous Elements and Compounds States of Matter Solids Liquids Gases Properties Physical vs Chemical Intensive vs Extensive Measurements International System of Units Length Mass Time Temperature and Amount Prefixes Density Direct Calculation By Displacement Temperature Numbers Scientific Notation Significant Figures Fahrenheit Celsius and Kelvin Multiplication and Division Addition and Subtraction Accuracy vs Precision Dimensional Analysis 2015 Marcus Jennings Chapter 1 Notes Data Ideas in Science There are two types of data quantitative and qualitative Quantitative data involves numbers and measurements Qualitative data involves observations about the subject s characteristics Ideas in the scientific world are in the form of hypotheses theories and laws A hypothesis is a potential explanation for several observations A theory is a principle that explains a body of facts or laws that are based on them but is A law is a statement that describes an interaction that is always true under the same set of not necessarily proven circumstances Matter Matter is anything that has mass and volume o There are two main types of mixtures In a homogeneous mixture the individual parts cannot be easily identified An example is salt water In a heterogeneous mixture the individual parts can be easily identified An example is a salad with several different vegetables o Pure substances exist in two forms elements and compounds An element is a pure substance that consists of only one type of atom Some examples include gold sulfur and carbon A compound is any pure substance that contains two or more elements Some examples are water salt and carbonic acid o Matter can exist in four states solids liquids gases and plasmas Solids have a definite volume and a definite shape Liquids have a definite volume but no definite shape Gases have no definite volume and no definite shape o The properties of matter can be described as chemical physical intensive and extensive Chemical properties are consequences of a substance s structure and are observable during reactions An example is a substance s ability to burn Physical properties are measureable An example is a substance s boiling point Intensive properties are qualities of matter that are independent of a substance s mass Some examples are density and temperature Density is a constant ratio of a substance s mass to its volume Temperature is intensive if two samples of water both at the same temperature are added together the mass of the sample increased but the temperature remained the same Extensive properties depend on the amount of matter being considered Some examples are mass length and volume 2015 Marcus Jennings Measurements o The International System of Units SI Length meter m Mass kilogram kg Time second s Temperature Kelvin K Amount Moles mol o Prefixes Tera T 1 x 1012 Giga G 1 x 109 Mega M 1 x 106 Kilo k 1 x 103 Deci d 1 x 10 1 Cent c 1 x 10 2 Milli m 1 x 10 3 Micro 1 x 10 6 Nano n 1 x 10 9 Pico p 1 x 10 12 o Density The ratio of mass to volume Direct Calculation By Displacement 1 mL 1 cm3 o Temperature From Celsius to Fahrenheit F C 32 From Fahrenheit to Celsius C F 32 From Celsius to Kelvin K C 273 15 F C at 40 2015 Marcus Jennings Numbers o The way we write numbers in calculations and data is significant o Scientific notation Represents numbers with decimals and powers of 10 To put a number into scientific notation Move the decimal so that the number is between 1 and 10 but not equal to either Count the number of decimal places moved If moved to the left the exponent is positive If moved to the right it is negative o Significant Figures Tells the precision and uncertainty of a number Theoretically all numbers can be interpreted as rounded values The general rules for significant figures are as follows o Any non zero digit is significant o Any zeros between non zero digits are significant o Any ending zeros after the decimal point are significant o Any leading zeros are NOT significant o Round to the least number of significant figures in the Multiplication and Division given numbers Addition and Subtraction o Round to the least number of significant decimal places based on the numbers given o Accuracy vs Precision Accuracy describes a value s closeness to the true absolute correct value Precision describes a values reproducibility o Dimensional Analysis The method of problem solving that emphasizes the relationships between units and ratios 2015 Marcus Jennings Chapter 1 Practice Problems 1 Identify the following as a hypothesis a theory or a law a If a plant is placed in an enclosure of green tinted glass then it will die because plants reflect green light b The sum of all forces acting on a system is equal to mass times acceleration c As an organism s environment changes it evolves into a new species with new characteristics that increase its ability to survive 2 Identify the following mixtures as homogeneous or heterogeneous a A solution of sodium chloride 3 State if the following are chemical or physical properties of matter b A pot of potato soup c A well blended smoothie a Color b Reactivity c Hardness d Ice melts 2015 Marcus Jennings 4 Explain the following a Volume is an extensive property b Density is an intensive property 5 What is the density in grams per cubic centimeter of a rectangular prism with length 12 3 cm width 3 6 cm height 7 941 cm and mass 783 grams 6 What volume in mL does a piece of metal with mass 324 grams and density 11 3 occupy 7 Convert 75 6 C to F 8 Convert 53 F to Kelvin 2015 Marcus Jennings 9 The standard unit for mass is the slugs The standard units for acceleration are the product of mass and acceleration and the standard unit is the pound Given that 1 slugs 14 9 kg 1 foot 0 305 m and 1 Newton 1 convert a force of 298 7 pounds to Newtons Force is 10 Convert a density of 12 36 g mL to kg m3 2015 Marcus Jennings 2015 Marcus Jennings 2015 Marcus Jennings 2015 Marcus Jennings
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