Obj. 1.4 to 1.6

 A.) Metric System 1.) All SI units (notes from Table 1.4)  B.) Selected Prefixes you should know 1.) Table 1.5  C.) Length and Mass 1.) Length is in meters 2.) Mass (amount of material in an object) is in grams

 D.) Temperature (helps determine the direction of heat flow, by describing the average kinetic energy) 1.) Always flows hot to cold 2.) Formulas  A.) K = C  B.) F = 9/5 (C) ) Scales  A.) Fahrenheit  B.) Celsius  C.) Kelvin Absolute Scale SI unit  E.) Volume (space occupied) 1.) SI unit is m³ (derived from length) 2.) Typically use L (metric but non-SI) 3.) important conversions 1mL = 1cm³ and 1L = 1dm³

 F.) Density = mass/volume 1.) how much matter per space occupied 2.) useful for qualitatively comparing how close particles of a substance are 3.) water is 1.00g/mL 4.) Typically when substances cool, densities are larger and vice versa. 5.) Particles that are less dense will float on more dense material as long as they are not miscible or soluble.

 A.) Precision – how closely individual measurements agree with one another (not always accurate)  B.) Accuracy – how closely individual measurements agree with the correct or “true” value  C.) Standard Deviation – number that describes the precision of many measurements. Smaller = more precise

 D.) Significant Figures – all digits of measured quantities including the last uncertain one is considered significant. 1.) Review of atlantic and pacific rules (you may use) 2.) Rules from text:  A.) zeros between nonzero digits are always significant  B.) zeros at beginning of a number are never significant  C.) zeros at the end of a number are significant if a decimal place is present  D.) all nonzero digits are significant  E.) scientific notation decimal movement will not change the number of significant figures

 E.) Significant Figures in calculations 1.) Adding and Subtracting  A.) The result has the same number of decimal places as the measurement with the fewest decimal places 2.) Multiplying and Dividing  A.) The result contains the same number of significant figures as the measurement with the fewest significant figures  ** at times, you may need to put your answer in scientific notation. Eg. you cannot round 2400 to 3 sig figs unless you put it in scientific notation, like 2.40 X 10 3

 A.) An approach to solve problems by canceling units  B.) Conversion Factor – a fraction whose numerator and denominator are the same quantity expressed in different units

 C.) Using two or more conversion factors 1.) you may create a sequence of conversion factors to get your desired unit. 2.) you may also convert both units in rate (m/s) or density (g/mL) with one sequence  D.) Conversions Involving Volume or Area 1.) If a conversion factor involves a metric unit that is squared or cubed, the factors’ number must be squared or cubed also

X X X 10 7