•The density of osmium, which is the densest metal, is 22.57g/cm3. What is the mass of a block of osmium that measures1.00cm x 4.00cm x 2.50cm?
•A students measures the mass of an object to be 355.6 g. Theaccepted mass of the object is 356.2 g. What is the studentspercent error?
•Write 0.0002503 in scientific notation
•Write 8.601 x 104 in numerical (Standard Notation)
DO-NOW
DO-NOW
•The density of osmium, which is the densest metal, is 22.57g/cm3. What is the mass of a block of osmium that measures1.00cm x 4.00cm x 2.50cm?
•A students measures the mass of an object to be 355.6 g. Theaccepted mass of the object is 356.2 g. What is the studentspercent error?
• What is the sum of 11.32 and 88.2?
•What is the product of 0.0020 and 56.20?
Temperature Scales
•Temperature
•A measure of how hot or cold something is
•Heat moves from the object at the higher temperature tothe object at the lower temperature
•Scientists commonly use two equivalent units oftemperature, degree Celsius (ºC) and kelvin (K)
Celsius (ºC) Temperature Scale
•The Celsius scale sets the freezing point of water at0°C and the boiling point of water at 100°C
•Known as the absolute scale
•Freezing point of water is 273.15 K and theboiling point is 373.15 K
Kelvin (K) Temperature Scale
Celsius
Kelvin
100
divisions
100
divisions
100°C
Boiling point
of water
373.15 K
0°C
Freezing point
of water
273.15 K
✴The zero point on the Kelvin scale, 0 K, or absolute zero,is equal to –273.15°C
Comparing the ºC and KTemperature Scales
•Add or subtract 273, to convert betweenCelsius and Kelvin scales, as shown in thefollowing equations:
Converting Between ºC and K
K = °C + 273
°C = K – 273
Normal human body temperature is 37°C.What is this temperature in kelvins?
PRACTICE PROBLEM:
PRACTICE PROBLEM
A student if performing an experiment and measuresthe temperature of water to be 350 K. What is thetemperature of the water in ºC?
TEMPERATURE SCALESPRACTICE
Chapter 3.3
DIMENSIONAL ANALYSIS
(From a measurement with one unit to an equivalentmeasurement with different units)
Commonly Used Metric Prefixes
Prefix
Factor
Kilo (k)
10 3 (1000)
Hecto (h)
10 2 (100)
Deca (D)
10 1 (10)
gram, liter, meter (g,l,m)
BASE UNITS
Deci (d)
10-1 (1/10)
Centi (c)
10-2 (1/100)
Milli (m)
10-3 (1/1000)
•A conversion factor is a ratio of equivalentmeasurements
•The two components of a conversion factor areequivalent measurements with different units...two waysof expressing the same quantity
•When a measurement is multiplied by a conversionfactor, the numerical value is usually changed, butthe actual size of the quantity measured remains thesame
Dimensional analysis is a way to analyze and solveproblems using the units, or dimensions, of themeasurements
•Useful for solving conversion problems
Example #1: How many minutes are in 5.5 hours?
Example #2: How many meters(m) are in 80centimeters(cm)?
Example #3: How many seconds are in a workday that lastsexactly eight hours?
Example #4: How many centimeters (cm) are in 505kilometers?
Example #5: The directions for an experiment ask eachstudent to measure 1.84 g of copper (Cu) wire. The onlycopper wire available is a spool with a mass of 50.0 g. Howmany students can do the experiment before the copper runsout?
Example # 6: The diameter of a sewing needle is 0.073 cm.What is the diameter in millimeters?
Example #7: The mass of these peppers was determined tobe 350.8 grams . What is the mass of the peppers inkilograms (kg)?
