1. Measurements are fundamental to science Measurements may be:
a. Qualitative
b. Quantitative

2. Measurements Qualitative Measurement: is a non- numerical measurement
Example: The solution turned brown when ammonia was added to iron (III) chloride

3. Quantitative Measurements
Quantitative Measurements: consist of two parts
a. A number
b. A scale (or unit)
Example:
The rock has a mass of 9.0 kg

4. SI Units and Prefixes The SI system used prefixes
“Kilo-” means 1000; symbol is k
“Hecto” means 100; symbol is h
“Deca” mean 10; symbol is da
“Base” means 1; meter/liter/gram
“Deci-” means 0.1; symbol is d
“Centi-” means 0.01; symbol is c
“Milli-” means 0.001; symbol is m
King Henry Died By Drinking Chocolate Milk

5. Length- is the distance between two points
The SI unit of length is the meter (m)
Devices used to measure length:
Rulers, Tape Measurers, and Meter Sticks

6. Volume (V) Volume- is the amount of space an object occupies
Volume of a cube is length * width * height
Volume of a cylinder is V=πr2h
The SI unit for volume is m3(meter cubed)
Other units for V: mL, cm3, dm3
The Liter (L) is also used for volume of liquids

7. Volume Continued
Conversions for volume:
1 dm3 (decimeter cubed ) = 1 L
1 cm3 = 1 mL (milliliter)= 1 cc
Devices Used to Measure Volume:
Ruler, Graduated Cylinder, Beaker

8. Mass-is the amount of matter that an object contains
SI Unit for Mass is measured in kilograms (kg)
Grams (g) are also used but are very small

9. Time- is the interval between two events Unit of time is the second

10. Temperature
Temperature- is the measure of the average kinetic energy of particles
Temperature is measured in Kelvin (K) in the SI system
K = °C
˚C= K- 273
Temperature is usually given in °C

11. Convert the following temperatures
°C to K
K to °C
K to °C
°C to K

12. Terms Used for Measurements
In comparing scientific results, the following terms are applied:
a. accuracy
b. precision

13. The closer the value is to the true value, the more accurate one is
Accuracy
Accuracy refers to the agreement of one experimental result to the true or accepted value
The closer the value is to the true value, the more accurate one is

14. hitting a three point shot determining the value of  to be 3.13
Accuracy
Examples of accuracy:
kicking a soccer goal
hitting a three point shot
determining the value of  to be 3.13

15. Practice: Tell if the accuracy is good or poor
a. Finding the percent H2O2 to be 2.9% (the bottle says it contains 3%)
b. Finding that a 2 Liter bottle only contains 1.5 Liters of soda
c. Filling a 1000 mL volumetric flask with 1050 mL of water

16. Precision
Precision refers to how close several different experimental values are to each other

17. Precision
Examples:
scoring three goals in a soccer game
Shooting an air ball five times
finding the value for  to be 3.12, 3.15, 3.13

18. Precision and Accuracy Problems
Precision problems usually arise from the skill of the person doing the experiment or the division of the measuring instruments
Accuracy problems usually related to the quality of the equipment used to make measurements

19. A student makes the following grades: a. 99, 100, 98, 100
Describe the accuracy and precision of the following as either good or poor
A student makes the following grades:
a. 99, 100, 98, 100
b. 45, 43, 44, 42
c. 100, 23, 60, 89