1. WARM -UP
CLASSIFY EACH SUBSTANCE AS APURE SUBSTANCE OR MIXTURE.IF IT’S A PURE SUBSTANCE, CLASSIFY AS AN ELEMENT OR COMPOUND.IF IT’S A MIXTURE, CLASSIFY AS HOMOGENEOUS OR HETEROGENEOUS
1. SWEAT
2.CARBONDIOXIDE
3.ALUMINUM
4.VEGETABLE SOUP

2. The units of measurements
Units – Standard quantities used to specify measurements
The two most common systems are the metric system and the English system
Scientists use the international system of units that is the metric system

3. 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
Intensity
Candella cd

4. Definitions
Meter – Measure of length – International bureau of weights and measures defined Meter as the distance light travels through vacuum in certain period of time(1/299,792,458 seconds) Kilogram – Measure of Mass – The mass of a metal cylinder kept at the International bureau of weights and measures at France Mass - The measure of quantity of matter within it Weight – The measure of gravitational pull on it The second – The measure of Time – Second is defined by the International bureau of weights and measures duration of 9,192,631,770 periods of the radiation emitted from a certain transition in a Cesium -133 The Kelvin – The SI unit of temperature

5. Three common temperature scales are 1. Fahrenheat scale (°F) 2
Three common temperature scales are 1.Fahrenheat scale (°F) 2.Celcius scale(°C) 3.Kelvin Scale(absolute scale)

6. Temperature Measurements
SI UNIT OF TEMPERATURE – KELVIN SCALE
THE OTHER UNITS OF TEMPERATURE ARE CELCIUS SCALE AND FAHRENHEAT SCALE
ABSOLUTE SCALE – ASSIGNS THE COLDEST TEMPERATURE AS 0 KELVIN. THERE IS NO NEGATIVE TEMPERATURE INVOLVED IN KELVIN SCALE
AT ABSOLUTE ZERO THERE IN NO OR MINIMAL MOLECULAR MOTION.

7. Equations
° F = 1.8(K - 273) + 32
°C = (°F-32)/1.8
K = °C+273.5

8. Temperature – Is the measure of average kinetic energy( energy due to motion) of the atoms or molecules. Temperature also determines the direction of thermal energy transfer called heat. Thermal energy always transfers from hot objects to cold ones

9. Choosing Prefix Multipliers
Scientific notations allows us to express very large or very small quantities in a compact manner
You have to choose the prefix multiplier close to the size of the quantity you are measuring
Examples: The radius of H atoms can be expressed as 1.06 × 10−10m
Kilo –1 km = 1000m= 103M
1mm= .001m = 10−3m

10. Prefix multipliers