1. Chapter 3 - Measurements
UNIT 1 Foundations
Chapter 3 - Measurements

2. Chapter 3C – Calculations with Measurements
Objectives:
State the reason for limiting the number of SDs in a calculated result
Add and subtract data and report the answer with appropriate SDs and units
Multiply and divide data and report the answer with appropriate SDs and units
Assignment: Section Review, page 73 and worksheet

3. Adding and Subtracting Data
Rules – Deals with PRECISION
The data must have the same units
The precision of a sum or difference cannot be greater than that of the least precise data given
Example
Add 3.1m and 45 cm

4. Multiplying and Dividing Data
Rules – uses SIGNIFICANT DIGITS & PRECISION
A product or quotient cannot have more SDs than the measurement with the fewest SDs
The product or quotient of a measurement and a pure number has the same number of decimal places, or same precision as the original measurement
Examples
7 x 2.35cm = 16.45cm not 16.5cm
2.63 cm/5 = 0.53 cm not 0.526cm

5. Rounding Review Identify the place value you are going to round to
If the digit to the right is 0-4 then it is unchanged, 5-9 the number goes up
If the rounded place value is to the right of the decimal point, all digits to the right of the rounded number will be dropped; if it is to the left than the numbers turn into zeros.
Examples in brown box on page 72

6. Chapter 3D – Measurement of Matter
Objectives:
Compare and contrast weight and mass
Summarize methods used to quantify matter
Calculate the volume of a solid with regular dimensions
Describe how the volume of a solid is determined using the displacement method
Calculate the density of a substance
Assignment: Section Review, page 79

7. Weight
Weight
Indicates the amount of matter, but does not measure the amount of matter directly
A measure of the earth’s gravity acting on the matter
Measure in Newtons, a unit of force
1 Newton = 0.224lb
Weight can change from place to place, different sea levels
Spring scale and an electronic scale both measure weight

9. Mass Mass A measure of the amount of matter in an object
Measured using a balance
Gravity is necessary to have in order to use the balance, but it cancels out on both sides so it is irrelevant
Electronic balance and inertia are other ways to measure mass

11. Volume Volume The space enclosed or occupied by an object
Regular Solid objects
Length x width x height or other formulas
Liquids
calibrated beaker, volumetric flask, pipette, graduated cylinder
The surface of a liquid is not flat. The curved surface is the meniscus and at its center is where the volume is read.
Water displacement method
Can be used to measure the volume of a small, irregular shaped solid

13. Density
Density
The amount of matter or the mass of the substance contained in a specific volumetric unit
Helps to identify certain kinds of matter
You can calculate the density if you know the mass and volume

15. TOMORROW Vocabulary Quiz Complete Chapter Review in Class
Includes all vocabulary throughout the entire chapter, PowerPoints, and board; not just the box at the end.
Complete Chapter Review in Class
Study for Chapter 3 Test