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Phy Sci Unit 2
Safety, Measurement, and the scientific method
| Question | Answer |
|---|---|
| What is a balance used for? | Measuring mass |
| What is a graduatated cylinder used for? | Measuring the volume of a liquid |
| What is a beaker used for? | It is NOT for measuring. It just holds chemicals. |
| What are some things you never do in the lab? | Never mix chemicals without asking or following directions, smell something directly, goof off, not tell the teacher when something spills or breaks, work without glasses or goggles, use the Bunsen burner without putting long hair back or sleeves up... |
| What is the safe way to smell something? | Waft it |
| What is the safe way to heat something in a test tube over a bunsen burner. | Use test tube tongs and hold it high up over the flame to heat it gently and DO NOT point it at anyone. |
| If you spill something, break something, or get hurt in the lab, what is the first thing you should do. | Let the teacher know! |
| Define Mass. | Mass is the amount of matter in something. |
| Define Volume. | Volume is the amount of space something takes up. |
| Define length. | Length is the distance between 2 points. |
| Define Temperature. | Temperature is how hot or cold something is because of the movement (kinetic energy) of its particles. |
| Define Time | Time is the interval between 2 events happening |
| What is the SI unit and measuring device for length? | meter, metric ruler or meterstick |
| What is the SI unit and measuring device for volume of a liquid? | L or mL, graduated cylinder |
| What is the SI unit and measuring device for mass? | g or kg, balance |
| What is the SI unit and measuring device for Temperature? | Degrees Celsius or Kelvin, thermometer |
| What is the SI unit and measuring device for time? | Second, stopwatch |
| Name the metric units from smallest to largest | milli, centi, deci, (base), deka, hecto, kilo |
| Which metric prefix means 10 | deka- |
| Which metric prefix means 1/10 | deci |
| Which metric prefix means 1000 | kilo- |
| Which metric prefix means 1/1000 | milli- |
| Convert 18 mm to cm | 1.8 cm |
| Convert 52 g to mg | 52,000 mg |
| Convert 1600 m to km | 1.6 km |
| What is a base unit? | One of the 7 defined standards for measurement in the SI system. With these 7 things you can measure everything! |
| What is a Standard? | An exact quantity people agree to use to compare measurements |
| The SI system is a base ___ system? | 10 |
| What are the 7 base units? | meter, kg, second, ampere, Kelvin, mole, and candela |
| What is a derived unit? | a unit of measure that comes from combining base units |
| What are some derived units? | cm2 - for area, cm3 - for volume, L - for voluem, mL - for volume g/mL for density, m/s - for speed... |
| What is density? | the mass per unit volume of something. This means how many particles are in a certain amount of space, or how compact the atoms are. |
| What is the equation for density? | D=m/V |
| Numbers in science have a __ and ___ | number and label or unit of measure |
| What is the density of a 25 g object that has a volume of 5.0 mL? | 5.0 g/mL |
| Scientist all report measurements the same way - all the digits they know from the lines on a device plus one "guess between the lines". What is this called? | Using significant digits or significant figures |
| What is precision on a measuring device mean? | A more precise measuring device will give you measurements to more decimal places. |
| If you take a measurement three times and all three measurements are very close to each other, are they accurate or precise? | precise |
| If you take a measurement and it is very close to the right answer, is it accurate or precise? | accurate |
| If your measurement for density is 8.3 g/mL and the right answer is 8.9 g/mL, what is your percent error. (O-A)/A x 100 | 6.7 % |
| When working with really large or small numbers in science to make them easier to write, scientist often us _______ ________. | scientific notation |
| Write this number in scientific notation 6,250,000 | 6.25 x 10 ^6 power |
| Write this number in scientific notation 0.00000000068 | 6.8 x 10 ^-10 power |
| Solve this problem and give your answer in scientific notation: 6.8 x 10 ^-10 power times 6.25 x 10 ^6 power | 4.25 x 10 ^-3 power |