1. English, SI, and Metric Systems
Measurement
English, SI, and Metric Systems

2. English System This is the system we use on a day-to-day basis.
The U.S. adopted the metric system in 1866.
The U.S. has not prohibited the use of “English” units in everyday life (i.e. construction, real estate, retail, and education.)
The U.S. has not made the crucial transition from "soft metric" to "hard metric", so that "1 pint (473 mL)" becomes "500 mL (1.057 pint)", with the traditional equivalent fading into smaller type sizes and finally disappearing.

3. Metric System Designed during the French Revolution of the 1790's
Brought a uniform measuring system to Europe
U. S. adopted its use in 1866 but has never fully converted to it.
Merchants, scientists, and educated people throughout Europe realized that a uniform system was needed, but it was only in the climate of a complete political upheaval that such a radical change could actually be considered.

4. SI System Revised version of the metric system adopted in 1960
Système International d'Unités, abbreviated as SI
Contains seven base units
All other units are calculated or derived from the basic seven.: length (meter), mass (kilogram), time (second), temperature (Kelvin), amount of substance (mole), electric current (ampere), luminous intensity (candela)

5. SI Base Units Quantity Unit Symbol Length meter m Mass kilogram kg
Time
second s
Temperature
Kelvin K
Amount of substance
mole
mol
Electric current
ampere A
Luminous intensity
candela cd

6. Common Measurement Quantities
Length – The distance from one place to another
Mass – The amount of matter in an object
Time – The measure of the duration of an event
Temperature – The measure of the average speed of the particles that make up a material
Volume – The amount of space an object takes up

7. Measurement Units Quantity English Metric SI Length Foot Meter Mass
Pound**
Gram
Kilogram
Time
Second
Temperature
Fahrenheit
Celsius
Kelvin
Volume
Gallon
Liter
Meter3
** Note: Pound is the English unit for weight. The seldom used slug is the
English unit for mass.

8. Length
Unit name: meter
Unit abbreviation: m

9. Length
For reference, 1 meter is a little longer than 1 yard or 3 feet. It is about half the height of a very tall adult. A centimeter is nearly the diameter of a dime, a little less than half an inch. A millimeter is about the thickness of a dime.

10. Length Tools Large – odometer Medium – meter stick Small – ruler
Very tiny – Vernier caliper

11. Mass
Unit name: kilogram
Unit abbreviation: kg

12. Mass
For reference, 1 gram is about the mass of a paper clip. One kilogram is about the mass of a liter of water.

13. Mass Tools
Triple beam balance
Electronic balance

14. Time
Unit name: second
Unit abbreviation: s

15. Time
Technical definition: The time needed for a cesium-133 atom to perform 9,192,631,770 complete oscillations.
In practice, every 3 calendar years will have 365 days, and every 4th year is a "leap year", which has 366 days, to make up for the extra quarter day over 4 years. The years 2008, 2012, and 2016 are all leap years. This gives us a total of 52 complete 7 day weeks in each calendar year, with 1 day left over (or 2 in a leap year).

16. Time Conversions
1 minute = 60 seconds 1 hour = 60 minutes = 3600 seconds 1 day = 24 hours 1 week = 7 days 1 year = days (for the Earth to travel once around the sun)

17. Temperature SI Unit name: Kelvin Unit abbreviation: K
Metric name: Celsius
Metric abbreviation: °C

18. Temperature In lab, we will use Celsius thermometers.
Temperatures must be converted to Kelvin when doing gas law problems.
Ice forms at 0°C and water boils at 100°C.
We will discuss temperature conversions during the gas law unit.

19. Amount of substance
Unit name: mole
Unit abbreviation: mol

20. THE MOLE Chemistry unit used to describe the amount of a substance.
We use it to describe amounts of very small things like atoms.
It is a counting unit, sort of like a dozen. (1 dozen = 12)
The mole is equal to x 1023 particles.

28. MOLE DAY Celebrated on October 23rd from 6:02 am to 6:02 pm
Celebrates Avogadro’s number: x 1023

29. Electric current
Unit name: ampere
Unit abbreviation: A

30. Luminous Intensity
Unit name: candela
Unit abbreviation: cd

31. SI Units You Need to Know
You will need to know the SI units for length, mass, time, temperature, and amount of substance.
Electric current and luminous intensity are physics units; therefore, you will not need to know these for the test.

32. Derived Units
From the 7 base units, all other units of measure can be determined using mathematical equations.
These units include area, volume, and density.

33. Area, Volume, & Density Area = length x length Area = m x m = m2
Volume = length x length x length
Volume = m x m x m = m3
Density = mass / volume
Density = kg / m3

34. Volume Tools Liquid – graduated cylinder
Rectangular solid = length x width x height
Irregular solid – water displacement

35. Density Amount of matter (mass) contained in a unit volume
Density is calculated by dividing the mass by the volume.
Material
Density (g/mL)
Water
1.000
Ice
0.917
Air
Gold
19.31

36. Density Tools
Equation Density = mass/volume
Units: g/mL