UNIT ONE TOPIC: Units of Measurement

Measurement You are making a measurement when you  Check your weight  Read a clock  Take your temperature  Weigh a cantaloupe What kinds of measurements did you make today?

Standards of Measurement When we measure, we use a measuring tool to compare some characteristic of an object to a standard.

Some Tools for Measurement

Learning Check U1 From the previous slide, name the tool (s) you would use to measure A. temperature____________________ B. volume ____________________ ____________________ C. time____________________ D. weight____________________

Solution U1 From the previous slide, state the tool (s) you would use to measure A. temperaturethermometer B. volume measuring cup, graduated cylinder C. timewatch D. weightscale

Measurement in Chemistry In chemistry we  make observations  qualitative - describe quality  quantitative- use numbers to report measurements

Learning Check U2 What are some U.S. units that are used to measure each of the following? A. length B. volume C. weight D. temperature

Solution U2 Some possible answers are A. length inch, foot, yard, mile B. volume cup, teaspoon, gallon, pint, quart C. weight ounce, pound (lb), ton D. temperature Fahrenheit degree (  F)

Metric System (SI) Is a decimal system based on 10 Used in most of the world Used by scientists and hospitals

Units in the Metric System length meter m volumeliter L mass gram g temperatureCelsius °C

Stating a Measurement In every measurement there is a Number followed by a Unit 4.23 cm The unit describes the standard used for comparison and the number tells how many of those units are needed to describe the quantity being measured.

Learning Check U3 What is the unit of measurement in each of the following examples? A. The patient’s temperature is 102°F. B. The sack holds 5 lbs of potatoes. C. It is 8 miles from your house to school. D. The bottle holds 2 L of orange pop.

Solution U3 A. °F (degrees Fahrenheit) B. lbs (pounds) C. miles D. L (liters)

Learning Check U4 Identify the measurement in metric units. A. John’s height is 1) 1.5 yards2) 6 feet3) 2 meters B. The volume of saline in the IV bottle is 1) 1 liter2) 1 quart3) 2 pints C. The mass of a lemon is 1) 12 ounces 2) 145 grams3) 0.6 pounds

Solution U4 A. John’s height is 3) 2 meters B. The volume of saline in the IV bottle is 1) 1 liter C. The mass of a lemon is 2) 145 grams