1. Unit I Review

2. Metric The Great Monarch King Henry Died By Drinking Chocolate Milk
Meanwhile
Nobles
Played
Tera 1012
Giga 109
Mega 106
Kilo 103
Hecta 102
Deca 101
Base unit 100
Deci
Centi 10-2
Milli
Micro µ 10-6
Nano 10-9
Pico

3. Here’s the Graphic
T G M k h D b d c m µ n p

4. Remember
If the UNIT you are changing to is a smaller one, then you would expect the NUMBER to get larger.
If the UNIT you are changing to is a larger one, then you would expect the NUMBER to get smaller.
Don’t forget to use the lines between Tera, Giga, and Monarch (and micro, nano, and pico) as a reminder to count that place, when converting from metric to metric.

5. Significant Digit Rules
All non-zero numbers are significant.
Zeros that represent a measured quantity are significant. If it is a “placeholder” it is not significant.
A zero between any two non-zero numbers is significant.
Zeros at the left of a number are NOT significant.

6. Significant Digit Rules
Zeros to the right of the decimal point are significant.
Zeros at the end of a whole number are not significant, unless there is a decimal point.
Example: (the zeros are NOT significant)
Example: (ALL of the zeros are significant)

7. Rounding Off Numbers If the number is less than 5, drop it.
If the number is 5 or more, drop it, and raise the preceding number by 1.
Examples – rounded off to 3 significant digits:
becomes 3.48
becomes 4.81
becomes 5.33
7.999 becomes 8.00

8. Multiplication of Numbers
Check the problem to see which number has the LEAST number of significant digits.
Round the answer to be the same number of significant digits.
Example:
Find the area of a rectangle 2.1 cm by 3.24 cm
Area = cm2
Round to 6.8 cm2

9. Division The same rule applies to division problems.
Find the number in the problem with the LEAST number of significant digits.
Round the answer to the same number of significant digits.

10. Matter

11. Pure Substances
Both elements and compounds are considered PURE substances, because the smallest part of them is not able to be separated, except by CHEMICAL MEANS.

12. Special Cases of Mixtures
Both alloys (metal-metal mixtures) and solutions (part of the mixture is dissolved in the remainder) are considered mixtures, because they can be separated by PHYSICAL MEANS.

13. Physical Means
When taking apart the mixture, none of the substances composing it are changed. They retain their properties, whether mixed, or separate.
All of the changes of state are considered a physical change. That includes:
Boiling
Freezing
Melting
Condensing

14. Possible Signs of a Chemical Change
Change in temperature – either increased, or decreased
Change in color, odor, or texture
Release of a gas (NOT boiling)
Formation of a precipitate
A solid forming from 2 liquids combining
May also change in color

15. Some Words That Indicate a Chemical Change
Rust
Digest
Corrode
Decay
Decompose
React with
Tarnish