Chemistry

Introductory level chemistry notes

Significant Figures

When recording a measurement, you cannot be more precise than the instrument, so a value is always comprised of all known digits plus one unknown.

• Digits 1 through 9 always count. (123)
• Zeroes before digits do not count. (0.00123)
• Zeroes in between digits do count. (1023 or 1.023)
• Zeroes after a decimal point and after a digit do count. (0.0012300)
• Zeroes after a digit in an integer value do not count. (123000)

Multiplication / Division: Round answer to fewest sig figs.

Addition / Subtraction: Round answer to fewest decimal places.

Metric Conversion Factors (x)

• Length (based on meter (m))
• Mass (based on gram (g))
• Volume (based on liter (L))

• 1,000 x = 1 kx
• 1 x = 10 dx
• 1 x = 100 cx or 1 * 10² cx
• 1 x = 1,000 mx or 1 * 10³ mx
• 1 x = 1,000,000 ux or 1 * 10⁶ ux
• 1 mL = 1 cm³ (cc)

• 1 mile = 5280 feet
• 1 km = 1 mile
• 1.609 km = 1 mile
• 2.54 cm = 1 in (exact)
• 1 lb = 0.4536 kg = 454 g
• 1 qt = 946.4 mL

Molecular Geometry