DO-NOW The density of osmium, which is the densest metal, is 22.57 g/cm3. What is the mass of a block of osmium that measures 1.00cm x 4.00cm x 2.50cm? A students measures the mass of an object to be 355.6 g. The accepted mass of the object is 356.2 g. What is the students percent error? Write 0.0002503 in scientific notation Write 8.601 x 104 in numerical (Standard Notation)

DO-NOW The density of osmium, which is the densest metal, is 22.57 g/cm3. What is the mass of a block of osmium that measures 1.00cm x 4.00cm x 2.50cm? A students measures the mass of an object to be 355.6 g. The accepted mass of the object is 356.2 g. What is the students percent 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 to the object at the lower temperature Scientists commonly use two equivalent units of temperature, degree Celsius (ºC) and kelvin (K)

Celsius (ºC) Temperature Scale Kelvin (K) Temperature Scale The Celsius scale sets the freezing point of water at 0°C and the boiling point of water at 100°C Kelvin (K) Temperature Scale Known as the absolute scale Freezing point of water is 273.15 K and the boiling point is 373.15 K

Comparing the ºC and K Temperature Scales The zero point on the Kelvin scale, 0 K, or absolute zero, is equal to –273.15°C Celsius Kelvin 100 divisions 100°C Boiling point of water 373.15 K 0°C Freezing point 273.15 K

Converting Between ºC and K Add or subtract 273, to convert between Celsius and Kelvin scales, as shown in the following equations: K = °C + 273 °C = K – 273

PRACTICE PROBLEM: Normal human body temperature is 37°C. What is this temperature in kelvins?

PRACTICE PROBLEM A student if performing an experiment and measures the temperature of water to be 350 K. What is the temperature of the water in ºC?

TEMPERATURE SCALES PRACTICE

Chapter 3.3 DIMENSIONAL ANALYSIS (From a measurement with one unit to an equivalent measurement with different units)

Commonly Used Metric Prefixes 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 equivalent measurements The two components of a conversion factor are equivalent measurements with different units...two ways of expressing the same quantity When a measurement is multiplied by a conversion factor, the numerical value is usually changed, but the actual size of the quantity measured remains the same

Dimensional analysis is a way to analyze and solve problems using the units, or dimensions, of the measurements Useful for solving conversion problems Example #1: How many minutes are in 5.5 hours? Example #2: How many meters(m) are in 80 centimeters(cm)?

Example #3: How many seconds are in a workday that lasts exactly eight hours? Example #4: How many centimeters (cm) are in 505 kilometers?

Example #5: The directions for an experiment ask each student to measure 1.84 g of copper (Cu) wire. The only copper wire available is a spool with a mass of 50.0 g. How many students can do the experiment before the copper runs out?

Example # 6: The diameter of a sewing needle is 0. 073 cm 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 to be 350.8 grams . What is the mass of the peppers in kilograms (kg)?