Chemistry (Chapter 3) Flashcards
S1) Measurement
A quantitative description that includes both a number and a unit.
S1) Scientific Notation
An expression of numbers in the form m x 10 ^n where m is equal to or greater than 1 and less than 10, and n is an integer.
S1) In scientific notation, the coefficient is always a number greater than or equal to one or less than ten. The exponent is an integer.
S1) To evaluate accuracy of a measurement, the measured valued must be compared to the correct value. To evaluate the precision of a measurement, you must compare the values of two or more repeated measurements.
S1) Accuracy
The closeness of a measurement to the true value of what is being measured.
S1) Precision
Describes the closeness, or reproducibility, of a set of measurements take under the same conditions.
S1) Accepted value
A quantity used by general agreement of the scientific community.
S1) Experimental Value
A quantitative value measured during an experiment.
S1) Percent Error
The percent that a measured value differs from the accepted value.
S1) Error
The difference between the accepted value and the experimental value.
S1) Percent Error (formula)
The absolute value of the error divided by the accepted value, multiplied by 100%.
S1) Toe evaluate the accuracy of a measurement, the measured value must be compared to the correct value. To evaluate the precision of a measurement, you must compare the values of two or more repeated measurements.
S1) Measurements must always be reported to the correct number of significant figures because calculated answers often depend on the number of significant figures in the values used in the calculations.
S1) Significant Figures
All the digits that can be known precisely in a measurement, plus a last estimated digit.
S1) How do you determine a significant figure in measurements? (6 steps)
1) Every non-zero digit is significant.
2) Zeros between nonzero areas are significant.
3) Left most zeros in front of non-zeros after a decimal are not significant. They are placeholders.
4) Zeros after a non-zero digit AND after a decimal are SIGNIFICANT.
5) Zeros at the right most end that lie to the left of an understood decimal point are NOT significant.
6) If a number is defined or counted, then a infinite number of significant..
S2) International System of Units
The revised version of the metric system, adopted by international agreement in 1960.
S2) All metric units are based on multiples of 10. As a result, you can convert between units easily.
S2) Scientist commonly use two equivalent units of measure, the degree Celsius and the kelvin.
S2) Meter
The base unit of length in SI.
S2) Liter
The volume of a cute measuring 10 centimeters on each edge; it is the common unprefixed unit of volume in the metric system.
S2) Kilogram
The mass of 1 L of water at 4 degrees Celsius; it is the unit of mass in SI.
S2) Gram (g)
A metric mass unit equal to the mass of 1cm^3 of water a 4 degrees Celsius.
S2) Weight
A force that measures the pull of gravity on a given mass.
S2) Energy
The capacity for doing work or producing heat.
S2) Joule (J)
The SI unit of energy; 4.184 J equal one calorie.
S2) Calorie (cal)
The quantity of heat needed to raise the temperature of 1g of pure water 1 degree Celsius.
S2) Kilogram (kg)
The mass of 1 L of water at 4 degrees celsius; it is the base unit of mass in SI.
S2) Temperature
A measure of the average kinetic energy of particles in matter; temperature determine the direction of heat transfer.
S2) Celsius Scale
The temperature scale on which the freezing point of water is 0 degrees Celsius and the boiling point of 100 degrees Celsius.
S2) Kelvin Scale
The temperature in which the freezing point of water is 273K and the boiling point is 373K; 0K is absolute zero.
S2) Absolute Zero
The zero point on the Kelvin temperature scale, equivalent to -273.15 degrees Celsius.
S2) Density
The ratio of the mass of an object to its volume.
S2) Density is an intensive property that depends only on the composition of a substance, not on the size of the sample.
BLANK CARD.
S3) Conversion Factor
A ratio of equivalent measurements used to convert a quantity from one unit to another.
S3) When a measurement is multiplied by a conversion factor, the numerical value is generally changed, but the actual size of the quantity measured remains the same.
S3) Dimensional analysis is a powerful tool for solving conversion problems in which a measurement with one unit is changed to an equivalent measurement with another unit.
S3) Dimensional Analysis
A technique of problem-solving that uses the units that are part of a measurement to help solve the problem.
