Unit 3: Measuring & Calculating
Reading
BJU Chemistry book: Ch. 3 "Measuring and Calculating"
AP Classroom begin Unit 2 'Compound Structures'
Topics
Labs
Air in Classroom (Density and Sig Figs lab)
Pool Cubes density weblab
BJU Chemistry book: Ch. 3 "Measuring and Calculating"
AP Classroom begin Unit 2 'Compound Structures'
Topics
- Unit conversions
- Significant Figures
- Calculations involving mass, volume, density, etc
Labs
Air in Classroom (Density and Sig Figs lab)
Pool Cubes density weblab
Rules for Counting Significant Figures
- Non-zero digits are always significant. For example, 123 has three significant figures.
- Zeros between non-zero digits are significant. For example, 1005 has four significant figures.
- Leading zeros (zeros to the left of the first non-zero digit) are not significant. For example, 0.0025 has two significant figures.
- Trailing zeros (zeros to the right of the last non-zero digit) are significant if a decimal point is present. For example, 1.20 has three significant figures, while 120 (without a decimal) has two.
- Trailing zeros in a whole number without a decimal point are ambiguous. For example, 100 could have one, two, or three significant figures, depending on the context. To avoid ambiguity, use scientific notation (e.g., 1 x 10^2, 1.0 x 10^2, or 1.00 x 10^2).
Rules for Calculations with Significant Figures
- Multiplication and Division: The result should have the same number of significant figures as the number with the fewest significant figures in the calculation.
- Addition and Subtraction: The result should be rounded to the same number of decimal places as the number with the fewest decimal places.
Handouts
| 0._air_in_the_classroom_lab__(measurement_&_sig_figs).docx |
| 0._air_in_the_classroom_lab__TAKE HOME VERSION_.docx |
| 0._pool_cubes_-_density_weblab.pdf |
| 0._pool_cubes_density_weblab_student_example.pdf |