Scientific Research Observe--qualitative & quantitative Formulate a hypothesis Experiment Formulate a theory Experiment Make conclusions Formulate a natural law--rarely done

Measurement mass--kg length--m time--s temperature--K amount of substance--mol electric current--A luminous intensity--cd

Measurement Prefixes giga(G)– mega(M)—10 -6 kilo(k)– hecto(h)– deka(da)– deci(d) centi(c) milli(m) micro(µ) nano(n)

Accuracy Precision Random error Systematic error

Significant Figure Rules Nonzero integers are significant Leading zeros are never significant Captive zeros are always significant Trailing zeros are only significant when there is a decimal present in the number Exact numbers have an infinite number of significant figures

Significant Figures x

Significant Figure Rules for Addition and Subtraction The answer has the same number of decimal places as the least precise measurement = = 5

Significant Figure Rules for Multiplication and Division The number of SF in the answer can be no greater than the number of SF in value with the least number of SF. 5.8 x = / 2 = 3

Temperature Conversions Fahrenheit to Celsius: (  F  32  F) x 5  C / 9  F Celsius to Fahrenheit: (  C x 9  F / 5  C) + 32  F

Temperature Conversions Celsius to Kelvin:  C Kelvin to Celsius: K  273

How many SF are in the following: a b c x d.2001 e. 5 x 10 5 f.41,000 g h

Round the following to 3 SF: a b c x d.2001 e. 5 x 10 5 f.41,000 g h

Perform the following using applicable SF rules: a b. 1  c. (2.050 x ) x (6 x 10 5 ) d. 200  8.5

Subatomic Particles Protons Neutrons Electrons Isotope formulae