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Chapter 3
Scientific Measurement
| Question | Answer |
|---|---|
| What is measurement? | a quantity that has a # and unit |
| What is accuracy? | correctness |
| What is precision? | repeatability |
| What is scientific notation? | makes very small or large #s manageable, coefficient between 1-10. |
| Rules | +/-: exponents must be the same x: add exponents division: subtract exponents |
| What are significant figures? | in measurement all digits that are known plus the last digit |
| What determines if a digit is significant? Rules! | 1. All nonzero digits are significant 2. All zeros between nonzero digits (sandwich zeros) are significant 3. Leading zeros are NOT significant 4. Trailing zeros: significant if there is a decimal in the # NOT significant, if there is no decimal |
| What is error? | experimental value-accepted value |
| What is percent error? | Error/accepted value x 100= __/100=_ |
| What is SI? | the metric system that was originally established in france |
| What are the base units? | meter, kilogram, the kelvin, the second, and the mole |
| What determines if a digit is significant? Rules! | 1. All nonzero digits are significant 2. All zeros between nonzero digits (sandwich zeros) are significant 3. Leading zeros are NOT significant 4. Trailing zeros: significant if there is a decimal in the # NOT significant, if there is no decimal |
| What is SI? | the revised metric system that was originally established in france |
| What are the base units? | meter, kilogram, the kelvin, the second, and the mole |
| What are the derived units? | bass units are the foundation |
| What is mass? | contrast with weight, which is amount of force due to gravity |
| What is volume? | a derived unit; comes from a combination of units 1mL=1cm to the 3rd power (or cc) |
| What is weight? | the amount of gravitational pull on an object |
| Kelvin conversion | K=C+273 C=K-273 |
| What is a conversion factor? | a ratio of equivalent measurement, and is equal to 1 |
| What is dimensional analysis? | a way to analyze and solve a problem using the units (dimensions) of the measurement |
| What is density? | the ratio of the mass of an object to its volume. Density=mass/volume |