1. 2.1 - Scientific Notation

2. Scientific Notation
Numbers that are extremely large can be difficult to deal with…sooo
Scientists convert these numbers into scientific notation
Scientific notation expresses numbers as a multiple of two factors:
A number between 1 and 10 (only 1 digit to the left of the decimal!)
Ten raised to a power

3. For example:
A proton’s mass = kg
If you put it in scientific notation, the mass of a proton is expressed as x kg
Remember:
When numbers larger than 1 are expressed in scientific notation, the power of ten is positive
When numbers smaller than 1 are expressed in scientific notation, the power of ten is negative

4. Try these: Convert 1,392,000 to scientific notation. = 1
Try these: Convert 1,392,000 to scientific notation. = x 106 Convert 0.000,000,028 to scientific notation. = 2.8 x 10-8

5. Adding and Subtracting using Scientific Notation
Make sure the exponents are the same!!
7.35 x x 102 = 9.78 x 102
If the exponents are not the same, you have to make them the same!!
Tip: if you increase the exponent, you decrease the decimal if you decrease the exponent, you increase the decimal
Example:
Tokyo pop: x 107
Mexico City pop: x 106 = 1.56 x 107
Sao Paolo pop: x 108 = 1.65 x 107
NOW you can add them together and carry thru the exponent
Total= 5.91 x 107

6. Multiplying and Dividing using Scientific Notation
Multiplication:
Multiply decimals and ADD exponents
Ex : (1.2 x 106) x (3.0 x 104) = 3.6 x = 10
* Ex: (1.2 x 106) x (3.0 x 10-4) = 3.6 x (-4) = 2
Division:
Divide decimals and SUBTRACT exponents
Ex: (5.0 x 108) ÷ (2.5 x 104) = 2.0 x – 4 = 4
*Ex: (5.0 x 108) ÷ (2.5 x 10-4) = 2.0 x – (-4) = 12

7. 2.2-2.3 - Measurements and Units

8. Units of Measure SI units: Systeme Internationale d’ Unites
standard units of measurement to be understood by all scientists
Base Units: defined unit of measurement that is based on an object or event in the physical world
there are 7 base units
some familiar quantities are time, length, mass, and temp

9. Time
second (s)
Many chemical reactions take place in less than a second so scientist often add prefixes, based on multiples of ten, to the base units.
ex. Millisecond
Length
meter (m)
A meter is the distance that light travels though a vacuum in 1/ of a second.
What is a vacuum?
Close in length to a yard.
Prefixes also apply…ex. millimeter

10. Mass mass is a measurement of matter kilogram (kg) about 2.2 pounds
Masses measured in most laboratories are much smaller than a kilogram, so scientists use grams (g) or milligrams (mg).
How many grams are in a kilogram?
1000
How many milligrams are in a gram?

11. Derived Units Not all quantities are measured in base units
A unit that is defined by a combination of base units is called a derived unit.
Volume and Density are measured in derived units.

12. Volume
The space occupied by an object
Unit = cm3 = mL
Liters are used to measure the amount of liquid in a container (about the same volume as a quart)
Prefixes also applied…ex. milliliter

13. Modified Table 2.1 – The Base Units
Quantity
Base Unit
Time
Second (s)
Length
Meter (m)
Mass
Kilogram (kg)
Temperature
Kelvin (K)
Amount of a substance
Mole (mol)
Electric current
Ampere (A)
Luminous intensity
Candela (cd)

14. Modified Table 2.2 – SI Prefixes
Symbol
Numerical Value in Base Units
Power of 10 Equivalent
Giga G
1,000,000,000
109
Mega M
1,000,000
106
Kilo K
1000
103 -- 1
100
Deci d
0.1
10-1
Centi c
0.01
10-2
Milli m
0.001
10-3
Micro
10-6
Nano n
10-9
Pico p
10-12