Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

Normal Size Small Size show me how

Normal Size Small Size show me how

# Chemistry Test 3-1

### measurements

Question | Answer |
---|---|

something that has magnitude, size, or amount | quantity |

size of a quantity determined by a measurement process and described by both a number and a unit | magnitude |

compare what is to be measured with a previously defined size | units of measurement |

the choice of unit depends on | the quantity being measured |

single measurement system agreed on by scientists all over the world | SI system |

some non-SI units are still used by __ | chemists |

objects or natural phenomena that are of constant value, easy to preserve, easy to reproduce and practical in size | standards of measurement |

standards are used to __ | compare |

basic quantities measured in arbitrary units established by international agreement | fundamental quantites |

used in measuring fundamental quantities | SI base units |

the distance between 2 points OR the path traveled by light in a vacuum during a time interval | length |

the amount of matter in a body | mass |

duration of an event OR vibrations of Cesium 133 | time |

degree of hotness or coldness of an object | temperature |

amount of substance | mole |

combinations of fundamental quantites so that combinations of units are produced | derived units |

how do you convert from C to Kelvin? | add 273 to the C |

used to figure out the # of atoms or molecules in a given amount of substance | mole |

number of units or fraction of a unit each line on the scale stands for | calibration |

what is the percent error formula/ | %E= Value a- Value e/Value a |

since most objects___ expand as the temperature increases, the volume ___ | expand; increases |

as volume ___ density ___ | increases; decreases |

good measurements are both ___ and ___ | accurate and precise |

refers to the closeness of measurements to the correct or accepted value of the quantity measured | accuracy |

what does accuracy depend upon? | 1. how carefully the measurement is done 2. quality of the instrument (in working order/well made) 3. one measruement or the average of one measurement as compared to the accepted value |

what is accuracy determined by? | percent error |

value accepted comes from ___ | books or tables |

value experimental comes from | the experiment or measurement in lab |

the numerator of the percent error formula is called ____ | absolute error |

refers to the closeness of a set of the same quantity made in the same way | precision |

what does precison depend upon? | 1. skillful estimation (your guess) 2. number of divisions in the instrument (calibration) 3. how close several measurements are to each other. |

one way to look at precison | standard deviation |

Created by:
lovecamille018