1. Chapter 2 Notes
Measurement -In science the SI (International System) system of measurement is used Types of Measurement 1) Qualitative -gives descriptive non-numeric results ex- feeling someone’s head for a fever *may be different from person to person

2. Quantitative
-gives definite numeric results
ex- using thermometer to check for fever

3. Scientific Notation ex→ 7. 82 x 103 -always a coefficient (in ex: 7
Scientific Notation ex→ 7.82 x 103 -always a coefficient (in ex: 7.82) multiplied by 10 raised to a power (in ex: 103) *coefficient must be a number ≥ 1 < 10 *the exponent shows how many times the coefficient is multiplied or divided by 10 -used to write small or large numbers

4. precision- how close a series of measurements are to one another accuracy- the closeness of measurements to the true value of what is being observed *Can be precise, but not accurate or vice versa -page 49 figure 3.1 -to evaluate the accuracy you must compare with the actual value

5. accepted value- correct value based on reliable references ex- boiling point of water = 100°C or 212°F experimental value- the value measured in the lab ex- measured bp of water = 99.1°C error- │experimental value – accepted value│ ex- error = │ 99.1°C - 100°C │ = 0.90°C

6. percent error = error X 100 accepted value ex- 0. 90°C X 100 100°C =0

7. Significant Figures -all the digits that can be known precisely in a measurement plus a last estimated digit Atlantic Rule -if a decimal point is absent, start counting from the first non-zero digit from the Atlantic Ocean side inland (right → left) Pacific Rule -if a decimal point is present, start counting from the first non-zero digit from the Pacific Ocean side inland (left → right) **All #’s significant when counting

8. Examples 1100m 0. 00130ML 2003g (2) (3) (4) 3000 cars 456 17

9. 10400L 308g m L 230L g 5600mg 200 pens

10. Rounding Sig Figs Round each number to 2 sig figs:

11. Multiplying/Dividing Sig Figs -the answer must have the same number of sig figs as the factor with the fewest sig figs Ex- (40)(56)(340) (1 sig fig) Ex ÷ (3 sig figs)

12. Adding/Subtracting Sig Figs -the result must have the same number of decimal places as the quantity with the fewest decimal places Ex (2 decimal places) Ex- 5.9 – (1 decimal place)

13. Metric System
-universal system of measurement used by scientists globally (SI)
-based on scales/multiples of 10
-uses prefixes to convert numbers
Length- size, distance
-basic unit is the meter (m)
1 meter = inches
-Find your height in meters!!!

14. Mass- the amount of matter in an object -basic unit is the gram (g) 1 kg = 2.2 lbs -Find your weight in kilograms!! weight- measure of the pull of gravity on a given mass -mass is always the same, but weight can change -weight on the moon is 1/6 your weight on the Earth -Find your weight on the moon!!

15. Volume- the amount of space an object occupies -basic unit is the Liter (L) 1 L = 1.06 quarts **1 milliliter = 1 cm3 HOW?? (length)(width)(height/thickness) = volume (cm)(cm)(cm) = cm3 (cc) = mL

16. Temperature- how hot or cold something is -basic unit is Celsius (°C) Conversions: °F = 1.8(°C) + 32 °C = 5/9 (°F – 32) Kelvin = K = °C °C = K ) 15°C = ?°F 1.8(15) = 59°F

17. 2) 37°F =. °C 5/9 (37-32) 5/9 (5) 2. 78°C 3) above to Kelvin 2
2) 37°F = ?°C 5/9 (37-32) 5/9 (5) 2.78°C 3) above to Kelvin 2.78°C = K Try These! 37°C = ?°F 72°F = ?°C and K