Chapter 2 Part II - PowerPoint PPT Presentation

Chapter 2Part II

Converting Between Units

Density

Temperature

• If the first digit to be removed is:
• 5 or greater then the preceding digit is increased by 1 (round up)
• Less than 5 then the preceding digit remains the same (round down)

• Round 1345.493 to:
• 2 decimal places
• 1 decimal place
• The 1’s (ones)
• The 10’s (tens)
• The 100’s (hundreds)

• Metric to Metric Conversions
• See board

• Miles  km
• Pounds  grams  kg
• mL  fluid ounces
• M  cm  inches

• Density = mass of an object

volume of object

• Units
• The mass of the object is expressed in grams
• The volume is expressed in:
• mL or cm3 for solids and liquids
• L for gases
• Density units:
• g/mL or g/cm3
• g/L
• Pounds/foot3 (English system)

• Density of water is ~ 1g/mL at room temperature.
• What is the approximate mass of water in a 0.5 L water bottle?
• What is the volume of 150 grams of water?

• Objects with a density greater than 1g/mL sink in water.
• Objects with a density less than 1g/mL float in water.

• The density of the elements can be found on the periodic table.
• Examples:
• The density of compounds must be looked up in reference “books”.

• Calculating density from data
• In class experiment

• Rearrange the density equation to solve for volume and mass:

Volume =

Mass =

• Calculate the mass, in grams and in pounds, of a gold brick
• see board for the dimensions of the gold brick

• Calculate the volume, in ml, of my gold cross
• Mass of cross: 4.5 g
• Round your answer to 2 decimal places

Temperature Scales (3)

• Fahrenheit
• Celsius
• Kelvin

TK =

TC =

TF =

• Shark fishing example
• Convert room temperature to:
• 0 C and K
• Sauna example