# Chem chap 2

 10^1 1*10=10 10^2 1*10*10=100 10^3 1*10*10*10=1000 10^4 1*10*10*10*10=10000 10^0 1 10^x * 10^y= 10^x+y 10^x/10^y 10^x-y what is scientific notation standard way of expressing large as well as small number  (large) greater than 1(small) less than 1 What is measurement? quantative observation - value number with a unit ex] length 225cm (Standard notation) - exponential notation decimal - between 1 & 10exponential part (10^x) Rules of expressing a number in scientific notation - Move the decimal to get a number between 1&10-When decimal is moved to left, the power is positive- when decimal is moved to right, the power is negative expressing using scientific notation 100.50 0.0380 5 100. 100 1.0050 * 10^23.80 * 10^-25 *10^01.00 * 10^21 * 10^2 Significant figures (digits) (sf) reflects precision of a given numbergreater the number of sf, greater is its precision 100 100. 100.0 100.00 1sf 3sf4sf5sf (highest precision) Rules of counting (sf) of a given number -all non zero digits are significant-leading zeros(zeros before a nonzero digit) are not significant ex] 0.000058 (2sf)- interior zeros (zeros after a nonzero digit) are significant ex] 100,005.78 (8sf)- trailing zeros (zeros after a nonzero digit) are significant, provided the number given with a decimal point 100 100. 100.00 0.00100500 100.500 1sf3sf5sf6sf4sf6sf Exact number number with unlimited sf.numbers reported by counting discrete objectsex] 30.0000 students 30 students -unlimited sfnumbers of a defined quantitiesex] 1m=100cm 1.000000m=100.0000 cm Rounding off number if digit is 4 or less, it is rounded downif digit is 5 or more, it is rounded upproceeding digit is increased by one Rules of sf in calculations The answer should be least precise as possible Multiplication and Division The answer should be least sf as possible Rules of sf for addition and subtraction The answer of least decimal places as possible Measurement-Quantitative observation Contains a number value and a unit Units- standard agreed upon quantities by which measurements are made(english unit)(metric unit)(scientist use SI unit) follows metric system of units Prefix Multipliers- Tera     T       10^12Giga     G       10^9Mega    M       10^6Kilo      K       10^3deci      d       10^-1centi     c       10^-2milli      m      10^-3micro    (mu)  10^-6nano     n       10^-9pico      p       10^-12 SI units (standard) of measurement Length-meter mvolume -cubicmeter m^3mass - kilogram   kgtemperature   kelvin  Ktime   seconds   s length is: measurement of distance between two pointsmeasured using a ruler Length: SI unit Metric unit English unit mkm, m, mm, nmin, ft, yd, mile Volume is: a measureof 3dimensional space occupied by an object-is a derived measurements with units of length (raised to the power of 3)-is measured using graduated cylinder Volume: SI unit Metric unit Eng unit Common unit laboratories m^3km^3, m^3, mm^3teaspoon, tablespoon, fl oz, cups, pints, gallon kL, L, cL, mL, (mu)L1mL=10^-3L 1cm^3=1mL=1cc volume= L*w*h1cm*1cm*1cmv=1cm^3 Mass is a measure  of quantity of material (matter)is measured using a balance weight is a measure of force of gravity acting up an object Mass: SI unit metric unit eng unit kgkg, mg, g, mu goz., lb  16 oz.----- 1lb. Unit conversion changing from one unit to another for particular measurementusing conversion factors derived from equivalents Density is: a measure of mass per unit volume is the ratio of mass to volume d=m/v How to find V= V= mass/ density How to find mass= M=d*v Authorbabyg7207 ID238040 Card SetChem chap 2 DescriptionChap 2 Chem Updated2013-10-01T05:23:01Z Show Answers