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| sec2.3 The terms ____?____ and _____?____ mean the same thing to most people,however in science their meanings are quite different. | Accuracy and precision are often thought to be the same in the nonscience communities although infact they are not the same by definition at all. |
| sec2.3 _____?______ refers to the CLOSENESS of measurements to the correct(or ACCEPTED) value of the quantity measured. | Accuracy |
| sec2.3 _______?______ refers to the CLOSENESS of a SET of measures of the same quantity made in the same way. | Precision |
| sec2.3 Measured values that are ______?_____ are close to the accepted value. | Accurate |
| sec2.3 Measured values that are close to one another, but NOT neccessarily close to the accepted value are calleed to be what? | Precise |
| sec2.3 The accuracy of an individual value or of an average experimental value can be compared quantitatively with the correct or accepted value by calculating the _______?______ | Percentage error |
| sec2.3 _________?_______ is calculated by subtracting the accepted value from the experimental value, dividing the difference by the accepted value, and then multiplying by 100. | Percentage error is (Value experimental - Value accepted) / Value accepted TIMES 100 |
| sec2.3 (V_experimental - V_accepted) / (V_acceptd) x 100 = ? | Percentage error where accepted value is V_accepted and experimental value is V_experimental |
| sec2.3 If the percentage error has a NEGATIVE value, then the accepted value is what compared to the experimental value? | GREATER |
| sec2.3 If the percentage error has a POSITIVE value, the accepted value is what compared to the experimental value? | Lesser |
| sec2.3 True or false? Some error or uncertainty ALWAYS exists in ANY measurement. | True |
| sec2.3 Skill of the measurer will place limits on the reliability of the measured results? | True, greater ability and more practice generally increases one's ability to be more precise and accurate. |
| sec2.3 The conditions of measurement does NOT affect the outcome? | False |
| sec2.3 The measuring instruments used for a measure places limitations on what? | Precision is limited by the device of use |
| sec2.3 Name at least three(3) factors affecting outcomes of measurements. | Human skill (skill of the measurer limits reliabilty) , instrument ability ( instrument can limit precision) , and conditions of the measurement |
| sec2.3 In science, measured values are reported in terms of what? | Any and all data reported between scientist should always have the numerical values expressed in their correct Significant Figures. |
| sec2.3 In a measurement , this consist of all the digits known with certainty plus one final digit, which is somewhat uncertain or is estimated. | Significant figures reported include all certain digits plus one uncertain digit. |
| sec2.3 True or false? In a significant figure, all the digits displayed are significant? | True, all the digits, including the estimated or uncertain digit, are significant. |
| sec2.3 Does the term significant mean certain,explain? | no...signifiant figures are such that each digit EXCEPT the last digit is certain---the last digit is uncertain or estimated. |
| sec2.3 In any correctly reported measured value , the final digit is _____?______ but not _____?____ | significant,certain......... |
| sec2.3 _______?______ are never reported , as chemistry students you will need to use and recognize significant figures when you work with measured quantities and report your results, and when you evaluate measurements reported by others. | Insignificant Figures , between reports, are never indicated.Final reports should only include SIGNIFICANT Figures including all its certain digits as well as the uncertain digit. |
| sec2.3 How many significant digits are there in the value 3.95? | three , two being certain and one being estimated or uncertain. |
| sec2.3 How many CERTAIN digits are in the value 887.8003 | six , in significant figures all digits are certain except the last estimated(or uncertain) digit--yet each is significant. |
| sec2.3 How many significant digits are there in 3 800 000? | two |
| sec2.3 How many certain digits are in the value 3 800 000 ? | six |
| sec2.3 How many significant figures are there in the value 7 000. ? | four |
| sec2.3 How many significant figures are in the value 7 000 ? | one |
| sec2.3 How many significant figures are in the value 7 000.0 | five |
| sec2.3 The significance of zeros in a number depends on their _____?_____. | location of zeros will decide if the zero is or is not significant, irregardless if that zero is certain or not. |
| sec2.3 If a value has only non-zero numbers, all the digits are _____?_____. | significant |
| sec2.3 A value that has zeros to left of the unshown decimal but to the right of any other non-zero numbers are _____?______. | nonsignificant |
| sec2.3 Any zero with a non-zero number to the left and to the right of a zero, that zero is considered to be what two things? | significant and certain |
| sec2.3 True or false? Zeros appearing between nonzero digits are significant. | true---any two nonzero numbers sandwiching that zero significant, but also makes the zero certain |
| sec2.3 Zeros appearing in front of all nonzero digits are _____?______. | not significant |
| sec2.3 Zeros at the end of a number and to the right of a decimal point are _______?____ | zero on right of decimal and at end of a number is SIGNIFICANT, but the last zero is considered to be uncertain or estimated too. |
| sec2.3 If a zero resides at the end of a number but to the left of a decimal point is ________?________ | can be significant or nonsignificant depending on circumstances of that value otherwise. |
| sec2.3 If a zero has not been measured or estimated but is just a _______?________, it is not significant. | placeholder |
| sec2.3 Zeros at the end of a number but to the left of a decimal point may or maynot be significant.If a zero has not been measured or estimated but is just a placeholder, it is not significant. A _________?_______ placed after zeros indicates that the zeros are significant. | decimal point |
| sec2.3 If the digit following the last digit to be retained is greater than 5, then the last digit should _______?______. | be increased by 1 |
| sec2.3 If the digit following the last digit to be retained is less than 5, then the last digit should _______?______. | stay the same |
| sec2.3 If the digit following the last digit to be retained is 5 followed by nonzero digit(s) , then the last digit should _____?_______ | increased by one to six |
| sec2.3 If the digit following the last digit to be retained is 5 but not followed by nonzero digit(s) and is preceeded by an ODD DIGIT, then the last digit should ______?_______. | increase by 1 to six because the certain value before the 5 is odd. |
| sec2.3 If the digit following the last digit to be retained is 5 but not followed by nonzero digit(s) and the preceeding significant digit is even then the last digit should be _____?_____. | the same...The last CERTAIN significant number being even indicates that is the uncertain digit is 5 it should remain the same if another nonzero value follows that 5. |
| sec2.3 When adding or subtracting decimals, the answer must have ________?______ digits to the right of the decimal point as there are in the measurement having the FEWEST digits to the right of the decimaql point. | the same number of digits |
| sec2.3 Mass divided by volume yields what? | Density |
| sec2.3 When using a calculator for calculations, you must realize that the degree of _______?_______ is not justified. | degree of certainty is not justified |
| sec2.3 For _______?_____ or _____?________, the answer can have no more significant figures than are in the measurement with the FEWEST number of significant figures. | for multiplication or division, answer can not possess greater number of significant figures than are in the measurement with the fewer number of significant figures. |
| sec2.3 Express 5.44 m - 2.6103 to the correct number of significant digits, note which are certain and which is uncertain? | 2.83 because: 5.44m -2.6103 is 2.8297 but 5.44 only has 3 significant digits and 2.6103 has 5 and 5.44 has 2 digits to right of decimal while 2.6103 has 4 to right of decimal.The answer can ,atmost, have two(2) digits to the right of the decimal.So 5.44-2.6103 = 2.83 so that the uncertain significant digit is 3 and the two certain digits are 2 and 8, there are three significant figuresin 2.83. |
| sec2.3 Conversion factors are used for what reason? | to change from one unit to another unit |
| sec2.3 Conversion factors are ____?____ because there is no uncertainty in them. | exact--conversion factors are considered to be exact entities. |
| Most exact conversion factors are defined, rather than ______?______; hence why conversion factors are considered to have no uncertain figures. | measured--measuring by definition leaves room for error depending on skill, instrument and conditions.Any measure is certain on to its second-to-last digit, the last digit is uncertain and therefore the value can not be exact. |
| sec2.3 _____?_______ numbers also produce conversion factors of unlimited precision. | counted numbers produce unlimited precision of conversional factors.There is no uncertainty in counted numbers nor conversion factors of counted numbers. |
| sec2.3 What do scientist call numbers that are written in the form of M x 10^n , where the factor M is a number greater than or equal to one(1) but less than ten and the superscripted "n" is a whole number. | Scientific Notation |
| sec2.3 Write 65 000 as a scientific number. | 6.5 x 10^4 |
| sec2.3 Write 0.00089 as a scientific number. | 8.9 x 10^-4 |
| sec2.3 Write 100 as a scientific number. | 1 x 10^2 |
| sec2.3 Write 80 050 as a scientific number. | 8.005 x 10^4 |
