Launch lab for chapter 3-matter and changes. Lab demonstration to show chemical properties and reactions between substances. Zinc metal and hydrochloric acid are used. Each element and/or compound is described by observation of physical properties. Each is tested for flammability in separate tubes and noted. The acid is placed into the zinc and the reaction noted, the formation of a gas. The gas is tested with a burning splint and the reaction observed and noted. The formation of a flame with a popping explosion along with a liquid forming in the test tube wall is noted. Discussion of the results observed and products formed followed

Continue with accuracy and precision of experimental results for density determination written on the board.
Use the average density from 2 trials, each with 3 results. One set of 3 from group A and one from B. Elicit the definition for accuracy of results by comparing experimental to accepted. Determine a formula for determining the error and discuss absolute value being used. Compare the error from both groups to each other. Note how to determine the percent error and discuss the differences seen when percent is use. Define and discuss precision in data. Note that precision and accuracy are not always equal. Work a problem as presented in the textbook

Define and determine the terms accuracy and precision a they apply to chemical experimental results. Utilize 3 density trials involving 2 groups of students as taken from the textbook. Note the results of all trials. Determine the average and note the accepted value taken from a table. Define, discuss, and determine the formula used to indicate the error in the experimental results. Discuss the absolute math value. Use the %error formula to determine the % error for each set of students. Discuss precision. Differentiate between accuracy and precision, and define precision. Work textbook problems from chapter

Continue how to determine accuracy and precision of chemical data. Reinforce workable definitions of accuracy including how to determine experimental values and used accepted values to determine accuracy percent. Utilize information from yesterday's determinations of density to determine error and percent error. Discuss precision of results. Use results from textbook to answer data questions and discuss their meaning

List an accepted value for the density of a substance X taken from a textbook. Show the results found by two groups of students, doing 3 trials each, and list them. Determine the average density for each group. Elicited which group produced the most accurate results, and define accuracy. Calculate the range of densities for each group's trials. Range for group A was 6 units and the range for group B was 2 units. Determine that group B had the more precise results, but not the most accurate. Determination of error and percent error will be shown tomorrow.

Indicate accuracy by showing two students throwing darts at a board. One student had his 3 darts hit in the bullseye and the second had his darts hit in the second layer right next to each other. Determine that the first dart thrower was more accurate. List 3 trials of density determination by using D=M/V. This will be continued tomorrow.

List a textbook quality as the density of a substance. Indicate this as the accepted value of 1.59g/cm^3. Show three trials by two groups of students, group A and group B. List the density determined from measurements of mass/uint and calculate the average. Group A average was 1.57 and group B average was 1.70. Determine which group was more accurate and define accuracy as how close a measure value is to an accepted value. Determine that group B's measurements were closer together but more precise. Define precision as how close the series of measurements are to each other. Define error as the experimental value minus the accepted value. Group A's error was 0.02 and group B's 0.11. Elicit the formula to determine % error. Group A was 1.26% and Group B was 6.91%

Define dihybrid. Use example of pea plants seed shape and color. Specify the dominant trait and indicate the letter shorthand for dominant and recessive. Record that yellow is dominant and round is recessive. Discuss the two possibilities for dihybrid, a dependent assortment or an independent assortment. Work a punnet square for dependent assortment, specify the phenotype and genotype ratios as 3:1 and 1:2:1 ratio. Define and discuss an independent assortment of alleles. Note the gametes formed and the possibilities of fertilization matches. Determine that a 16 square punnet is required and indicate all the possible gamete alleles and crosses. Determine the ratios and state their dominance/recessive ratio

Calculate the atomic mass of an element from its isotopes. For elements with only one isotope, the value of the mass is the weight of that single isotope. Example is gold. Elements with 2 or more isotopes would require the mass of each isotope and the relative amounts of each isotope. Example would be silver. Use of a spectrophotometer indicates that isotope 1 of silver has a mass of 106.903 AMU and a sample of silver contains 51.35% of that isotope. Isotope 2 mass is 108.900 and the % is 48.65%. Determine that the atomic mass of silver is found
by multiplying the % of each isotope given in decimal units x the mass of each isotope and adding the sum.
(0.5135 x 106.92) + (0.4865 x 108.900) = 107.84 AMU

Discuss and utilize the displacement of water to determine the volume of an irregularly shaped solid. Record initial and final volumes of water displaced after the mass of the solid is determined to the nearest 0.01 g is completely immersed in water. Calculate the density of the solid. Calculate the density of a square block of wood from its measured mass and volume determine by l x w x h in centimeters. Observe that the wood block will float. Determine the density of different objects with densities less than 1 and greater than 1. Detertmnine the relationship between an objects ability to float and the density.