Question | Answer |
How is WEIGHT different from MASS? | Weight - is a measure of the pull of gravity Ex. a man weighs 165 lbs on earth, but only 27.5 lbs on the moon |
Unit for mass in metric system | GRAM - 454 g = 1lb. |
Significant figures | In a measured number, significant figures are all the digits including the estimated digit |
Measure numbers | Measured numbers are obtained when one measures a quantity |
How to tell what is a significant number? (4) | 1. Not a zero 2. a zero between nonzero digits 3. a zero at the end of a decimal number 4. any digit in a coefficient of a number written in scientific notation |
Exact numbers | Exact numbers are clearly defined (60 minutes in an hour) |
Round off rules (2) | if four or less, round down, 5 or more, round up |
Multiplication & division-significant numbers | In multiplication or division, final answer contains #of significant figures as the measurement with the FEWEST significant figures Ex. 24.65 x 0.67 = 16.5155 - round to 17 (because 0.67 has just TWO significant figures) |
Prefixes - trillion, billion, million & thousand | 1. trillion - tera 2. billion - Giga 3. Million - MEGA 4. thousand - Kilo |
Prefixes (decrease size of unit) | tenth, hundredth, thousandth, millionth, billionth, trillionth, quadrillionth |
tenth, hundredth, thousandth, millionth, billionth, trillionth, quadrillionth | tenth-deci, hundredth-cent, thousandth-milli, millionth-micro, billionth-nano, trillionth-pico, quadrillionth -femto |
cm3 - cubic centimeter-dimensions | 1 cm x 1 cm x 1 cm- measures VOLUME and equals 1 mL = 1cm3 = 1cc |
Mass - how is "weight" recorded? | In kilograms |
Density | RELATIONSHIP of the MASS of object to its VOLUME |
Density measurements | grams per cubic centimeter (g/cm3) grams per milliliter (g/mL) or grams per liter (g/L) |
6.00 divided by 0.2000 | 30.0 - because when dividing, the answer must have same number of significant figures as the one with fewest digits--sometimes you have to add |
d = m divided by V | Remember: alphabetically divide so that DENSITY = Mass divided by Volume |
Add decimals | Answer should have same number of DECIMALS as that having fewest decimal places |
1 mL equals (write 3 ways) | 1 mL = 1 cm 3power = 1cc = .001 liter |
how many 3s, 3p & 3d orbitals are there? | 1, 3 & 5 respectively |
atomic radius | Size sinks, radius says size, radius sinks to bottom |
Size - rank Boron, chlorine, flourine & alumimium (look at position on chart-bottom left corner is biggest in size) | flourine<boron<chlorine<aluminum |