Abelard and Heloise
Chapter 1 The Chemical World
Chemistry a science that studies matter – its properties and changes. Matter is anything that has mass and takes up space. Matter is made up of atoms and molecules.
Scientific Method
Observation of nature → Hypothesis (possible explanation) → Experiments to confirm or revise hypothesis
Many observations lead to scientific law – a statement of the relationship between different parts of nature. Ex: law of conservation of mass- “ matter is neither created or destroyed” aka “the number and kind of atoms before a chemical reaction must be the same as after a reaction”. A theory describes a broader explanation of nature. Over time theories and laws are changed.
Chapter 2 Measurement and Problem Solving
Measurements have 1) numbers, 2) units, 3) uncertainty. The last digit is uncertain. Only one digit in a measurement is uncertain.
Scientific Notation
Decimal part x exponential part : X.YZ x 10abc
Only one digit left of the decimal point!
100 = 1 Positive exponents are numbers bigger than one.
101 = 10 10-1 = 1/10 = 0.1 Negative exponents are numbers smaller than one.
102 = 100 10-2 = 1/100 = 0.01
CALCULATOR KEYSTROKE SEQUENCE IS MISSION CRITICAL
Convert to scientific notation
5983 Express as number with only one digit left of decimal point 5.983 Count the number of decimal places moved: if move to left exponent is positive 5.983 x 103
0.005983 5.983 x 10-3 if move to right exponent is negative
Convert from scientific notation to decimal notation
Move the decimal to the left if the exponent is negative. 3.456 x 10-4 = 0.0003456
Move the decimal to the right if the exponent is positive. 3.456 x 104 = 34560
Significant Figures
Significant Figures are rules to express measured quantities with the correct amount of precision and uncertainty.
Thing that are counted (number of pennies or students) do not have sig figs or unlimited sig figs. Definitions of quantities
Chemistry a science that studies matter – its properties and changes. Matter is anything that has mass and takes up space. Matter is made up of atoms and molecules.
Scientific Method
Observation of nature → Hypothesis (possible explanation) → Experiments to confirm or revise hypothesis
Many observations lead to scientific law – a statement of the relationship between different parts of nature. Ex: law of conservation of mass- “ matter is neither created or destroyed” aka “the number and kind of atoms before a chemical reaction must be the same as after a reaction”. A theory describes a broader explanation of nature. Over time theories and laws are changed.
Chapter 2 Measurement and Problem Solving
Measurements have 1) numbers, 2) units, 3) uncertainty. The last digit is uncertain. Only one digit in a measurement is uncertain.
Scientific Notation
Decimal part x exponential part : X.YZ x 10abc
Only one digit left of the decimal point!
100 = 1 Positive exponents are numbers bigger than one.
101 = 10 10-1 = 1/10 = 0.1 Negative exponents are numbers smaller than one.
102 = 100 10-2 = 1/100 = 0.01
CALCULATOR KEYSTROKE SEQUENCE IS MISSION CRITICAL
Convert to scientific notation
5983 Express as number with only one digit left of decimal point 5.983 Count the number of decimal places moved: if move to left exponent is positive 5.983 x 103
0.005983 5.983 x 10-3 if move to right exponent is negative
Convert from scientific notation to decimal notation
Move the decimal to the left if the exponent is negative. 3.456 x 10-4 = 0.0003456
Move the decimal to the right if the exponent is positive. 3.456 x 104 = 34560
Significant Figures
Significant Figures are rules to express measured quantities with the correct amount of precision and uncertainty.
Thing that are counted (number of pennies or students) do not have sig figs or unlimited sig figs. Definitions of quantities