CHEM 1020 Scientific Notation

Scientific Notation

• Scientific notation expresses numbers as a decimal part (between 1 and 10) multiplied by 10 raised to an exponent.
• The exponent indicates the number of times 10 needs to be multiplied (positive) or divided (negative) by the decimal part.

Writing Very Large and Very Small Numbers

• A positive exponent multiplies 10 by itself a set number of times
• A negative exponent divides 1 by 10 a set number of times

Converting to Scientific Notation

• Identify the decimal part (number between 1 and 10)
• Move the decimal to obtain the number between 1 and 10
• Multiply by 10 raised to the appropriate power to reflect the movement
• A left move is positive, a right move negative

Metric Prefixes

• Prefixes like nano, micro, milli, centi, deci, deca, hecto, kilo, mega, and giga modify base units like meters, grams, and liters, scaling them up or down.

Commonly Used Units (CHEM 1020)

• Mass: Standard unit = grams; abbreviation= g. Milligram is one thousandth of a gram.
• Volume: Standard unit = liters; abbreviation = L. Milliliter is one thousandth of a liter. A milliliter is also equal to a cubic centimeter.
• Density: Standard units = grams per milliliter or grams per cubic centimeter
• Distance: Standard unit = meters; abbreviation = m. A kilometer is 1000 meters, centimeter is one hundredth of a meter, and a millimeter is one thousandth of a meter.

Numbers

• Exact Numbers: Numbers derived from counting or definitions, have no uncertainty.
• Measured Numbers: Numbers obtained from measurements always have some degree of uncertainty. This depends on the accuracy of the measuring tool.