Quick Reference: Measurements & Units

Matter

• Matter is anything that has mass and occupies space.

Measurements

• Measurements are the process of determining the extent of dimensions, quantity, or extent of something.
• Essential to answer questions like "How much…?", "How long…?", and "How many…?".
• WHAT GETS MEASURED, GETS IMPROVED!

SI Units and Prefixes

• The International System of Units (SI) is the convenient modern version of the metric system.
• Prefixes modify base units to indicate size relative to the base unit (e.g., milli-, kilo-, micro-).

Dimensional Analysis

• Dimensional Analysis uses conversion factors in a ratio form to change units.
• Steps:
  1) Write the unknown quantity with its units.
  2) List all needed conversion factors.
  3) Start with the known quantity and multiply by the appropriate conversion factors, cancelling units to obtain the desired units.

Metric and English Conversions

• Mass:
  $1\ \text{lb} = 454\ \text{g}$
  $1\ \text{kg} = 2.2\ \text{lb}$
  $1\ \text{oz} = 28.35\ \text{g}$

• Length:
  $1\ \text{in} = 2.54\ \text{cm}$
  $1\ \text{m} = 39.37\ \text{in}$
  $1\ \text{ft} = 12\ \text{in}$
  $1\ \text{mi} = 1.609\ \text{km}$
  $1\ \text{km} = 0.62137\ \text{mi}$
  $1\ \text{\AA} = 10^{-10}\ \text{m}$

• Volume:
  $1\ \text{qt} = 946\ \text{mL}$
  $1\ \text{L} = 1.057\ \text{qt}$
  $1\ \text{L} = 2.12\ \text{pints}$
  $1\ \text{L} = 4.23\ \text{cups}$
  $1\ \text{tsp} = 4.93\ \text{mL}$
  $1\ \text{tbsp} = 14.79\ \text{mL}$
  $1\ \text{fl oz} = 29.06\ \text{mL}$
  $1\ \text{gal} = 3.79\ \text{L}$

Temperature Scales and Conversions

• Fahrenheit from Celsius: $F = \frac{9}{5}C + 32$
• Celsius from Fahrenheit: $C = \frac{5}{9}(F - 32)$
• Celsius to Kelvin: $K = C + 273$
• Kelvin to Celsius: $C = K - 273$