Presentation on theme: "Measuring with SI Units"— Presentation transcript:
1 Measuring with SI Units 3.2Measuring with SI UnitsAll measurements depend on units that serve as reference standards. The standards of measurement used in science are those of the ____________ system.The International System of Units (abbreviated _________, after the French name, Le Système International d’Unités) is a ________ version of the metric system.
2 Measuring with SI Units 3.2Measuring with SI UnitsThe five SI base units commonly used by chemists are:the ______________,the ______________.
4 3.2Units and QuantitiesUnits of LengthIn SI, the basic unit of length, or linear measure, is the ___________ (m). For very large or and very small lengths, it may be more convenient to use a unit of length that has a prefix.
8 _______________, a non-SI unit. 3.2Units and QuantitiesUnits of VolumeThe SI unit of volume is the amount of space occupied by a cube that is 1 m along each edge. This volume is the cubic meter (m)3. A more convenient unit of volume for everyday use is the_______________, a non-SI unit.A liter (L) is the volume of a cube that is 10 centimeters (10 cm) along each edge (10 cm 10 cm 10 cm = _______________ cm3 = 1 L).
9 Common metric units of volume include 3.2Units and QuantitiesCommon metric units of volume includethe ______________, __________, (cubic centimeter), and microliter.
11 3.2Units and QuantitiesThe volume of _______ drops of liquid from a medicine dropper is approximately ________.A ________ cube has a volume of 1 cm3. ________is the same as ____________.These photographs above give you some idea of the relative sizes of some different units of volume. a) The volume of 20 drops of liquid from a medicine dropper is approximately 1 mL. b) A sugar cube is 1 cm on each edge and has a volume of 1 cm3. Note that 1 mL is the same as 1 cm3. c) A gallon of milk has about twice the volume of a 2-L bottle of soda. Calculating How many cubic centimeters are in 2 liters?A ___________ of milk has about __________ the volume of a ________ bottle of soda.
12 3.2Units and QuantitiesUnits of MassThe mass of an object is measured in comparison to a standard mass of 1 kilogram (kg), which is the basic SI unit of mass.A gram (g) is 1/1000 of a kilogram; the mass of 1 cm3 of water at 4°C is 1 g.
13 3.2Units and QuantitiesCommon metric units of mass include _______________, ___________, milligram, and microgram.
15 3.2Units and QuantitiesWeight is a ____________ that measures the ___________ on a given mass by gravity.The astronaut shown on the surface of the moon weighs one sixth of what he weighs on Earth.An astronaut’s weight on the moon is one sixth as much as it is on Earth. Earth exerts six times the force of gravity as the moon. Inferring How does the astronaut’s mass on the moon compare to his mass on Earth?
16 _________________ is a measure of how hot or cold an object is. 3.2Units and QuantitiesUnits of Temperature_________________ is a measure of how hot or cold an object is.Thermometers are used to measure temperature.Thermometers are used to measure temperature. a) A liquid-in-glass thermometer contains alcohol or mineral spirits. b) A dial thermometer contains a coiled bimetallic strip. c) A Galileo thermometer contains several glass bulbs that are calibrated to sink or float depending on the temperature. The Galileo thermometer shown uses the Fahrenheit scale, which sets the freezing point of water at 32°F and the boiling point of water at 212°F.
17 3.2Units and QuantitiesScientists commonly use two equivalent units of temperature, the ___________ ____________ and the ______________.
18 The zero point on the Kelvin scale, 0 K, or 3.2Units and QuantitiesOn the Celsius scale, the freezing point of water is 0°C and the boiling point is 100°C.On the Kelvin scale, the freezing point of water is kelvins (K), and the boiling point is K.The zero point on the Kelvin scale, 0 K, orabsolute zero, is equal to _____________°C.
19 3.2Units and QuantitiesBecause one degree on the Celsius scale is equivalent to one kelvin on the Kelvin scale, converting from one temperature to another iseasy. You simply __________ or _________ 273, as shown in the following equations.
20 Conversions Between the Celsius and Kelvin Scales 3.2Units and QuantitiesConversions Between the Celsius and Kelvin ScalesThese thermometers show a comparison of the Celsius and Kelvin temperature scales. Note that a 1°C change on the Celsius scale is equal to a 1 K change on the Kelvin scale. Interpreting Diagrams What is a change of 10 K equivalent to on the Celsius scale?
23 Energy is the capacity to do work or to produce heat. 3.2Units and QuantitiesUnits of EnergyEnergy is the capacity to do work or to produce heat.The joule and the calorie are common units of energy.
24 The joule (J) is the SI unit of energy. 3.2Units and QuantitiesThe joule (J) is the SI unit of energy.One _______________ (cal) is the quantity of heat that raises the temperature of 1 g of pure water by 1°C.