1. Chapter 12

2.  Celsius and Fahrenheit scales are the two most commonly used scales.  They were both designed with reference to the freezing point and boiling point of water  Positions were marked on a thermometer for these two temperatures and graduates were made in equal increments  Celsius is used more often around the world

3.  The size of a Celsius degree is larger than that of a Fahrenheit degree by a factor of 9/5.

4.  Introduced by William Thompson (Lord Kelvin)  Not expressed with the word “degrees”  SI base unit for temperature  Based on the concept of absolute zero.absolute zero

5.  Measure changes in thermometric properties  Several types exist including  Thermocouple  Electric resistance thermometers  Thermograph or thermogram  Type needed depends on goal of research and necessary procedure  Here, we will use a regular mercury or alcohol thermometer.

6.  Linear Expansion is the increase in one dimension of a solid due to an increase in temperature.  The length (L o ) of an object changes by an amount (∆L) when its temperature changes by an amount (∆T). α is the coefficient of linear expansion. α is a constant. This constant is a numerical description of the degree of thermal expansion solids will undergo when heated. Values can be obtained in your text (p.365) or online.

7.  Thermal Stress – buildings using steel supports must account for expansion in order to prevent “buckling” of steel beams  Bimetallic Strip – used in coffee pots, thermostats, etc.  Expansion of Holes – A hole in a piece of solid material expands when heated and contracts when cooled, just as if it were filled with the material that surrounds it.  Holes with larger coefficients of linear expansion expand more than those in materials with smaller coefficients.

8.  It makes sense that if the length of an object expands when heated, the volume would too.  The volume (V 0 ) of an object changes by an amount (∆V) when its temperature changes by an amount (∆T). β is the coefficient of volume expansion.

9.  If water at 0°C is heated, its volume decreases until the temperature reaches 4°C.  Above 4°C, water behaves normally and volume will increase as temperature increases.  The density of water is greatest at 4°C. Click here to find out why volume of ice is greater than volume of water.