Chem Notes

Scientific Measurments: Systems International (SI)

☈ Length- Meters (m)

☈ Weight- Kilograms (Kg)

☈ Volume- Liters (L)

☈ Time- Seconds (s)

☈ Electric Current- Amperes (amp)

☈ Temp.- Kelvin (K) *absolute zero = -2730 K

☈ Amount of Sub- Mole (mol)

☈ Luminous Intensity- Candela (Cd)

Prefixes:

Prefix Symbol Meaning Multiplier

(numerical) Multiplier

(exponential)

Mega M Million 1,000,000 1 x 106

Kilo k Thousand 1,000 1 x 103

Meter, Grams, Liters m, g, L None None 1 x 100

Deci d Tenth 0.1 1 x 10-1

Centi c Hundredth 0.01 1 x 10-2

Milli m Thousandth 0.001 1 x 10-3

Micro  Millionth 0.000001 1 x 10-6

Nano n Billionth 0.00000001 1 x 10-9

Pico p Trillionth 0.000000000001 1 x 10-12

Significant Figure Rules:

1. Digits other than zero are always significant.

96L 61.4g 4.512g

(3sf) (3sf) (4sf)

2. Zeros to the right to the decimal are significant when they have a number preceding them that is not zero.

4.72 4.7200 82.0

(3sf) (4sf) (3sf)

3. Zeros between two other numbers that are not zero are significant.

4. Find number with least number of significant figures report answer with that number of significant figure.

Hazard Sign:

Health- Blue

Flammability- Red

Reactivity- Yellow

White- Special Hazard Info

Safety Rules:

☠ No eating, drinking, or chewing gum

☠ Follow directions; ask for clarification

☣ Do not perform an unauthorized experiment

☣ Keep aisles clear

☣ Goggles and smock on all times

☣ Dispose chemicals properly

☠ Tie back long hair; no loose, baggy clothes and sandals

☠ Report all accidents

☠ Treat all chemicals as dangerous

☠ Stand up always; never sit unless instructed

☠ Never smell chemicals directly

☠ Do not place hands near mouth or eyes

☠ Turn off gas if burner goes out

☠ Abide any verbal requests by teacher

Parts of an experiment:

Dependant Variable-

-This is the response you are measuring

Independent Variable-

-Unaffected

Control-

-What you use as comparison

Constants-

-Never change

Sources of error:

✗ Procedural-

✓ Miss step

✓ Incorrect assumption

✓ Incorrect measuring

✗ Systematic-

✓ Consistency

✗ Random-

✓ Source of error due to the estimation of last significant figure

✓ More trials the less random errors

Formula for % of error:

Experimental data - Theoretical data x 100

Theoretical data

Scientific method:

I. Problem

II. Background information

III. Form Hypothesis

IV. Conduct experiment

V. Gather Data

VI. Analyze data- form conclusion

VII. Rinse and repeat

Periodic Table:

Mendeleev-

☸ Credited for the first periodic table

☸ Arranged elements in increasing mass

Moseley-

☸ Arranged elements in order of increasing atomic number

☸ Proposed Modern Periodic Law

☢ Chemical properties of elements are periodic

functions of their atomic number

Groups-

☸ Elements