Recitation 2 Last Name First Name 1 Identify each pure substance below as an element E or a compound C Calcium Ca Ozone gas O3 Sulfur S8 Magnesium Sulfide MgS Argon gas Ar Sodium Phosphate Na3PO4 Potassium fluoride KF Titanium Ti 2 For each of the following descriptions identify the law that best fits and fill in the chart with the letter a b or c that corresponds to the law a Law of Conservation of Mass b Law of Definite Proportions Law of Constant Composition c Law of Multiple Proportions Law Description The elements Phosphorus and Oxygen may form two different compounds P2O5 and P4O6 Sodium Chloride NaCl whether isolated from sea water or created by a chemical rection of sodium metal and chlorine gas will always have the chemical formula NaCl A researcher measures the masses of a chemical reaction s reactants prior to the reaction and products after the reaction These masses should be the same according to which of the laws 3 A researcher reacts baking soda NaHCO3 with vinegar acetic acid CH3COOH in two experiments In the first experiment 1 the researcher forgot to trap the carbon dioxide gas produced in the experiment In the second experiment 2 the researcher trapped the carbon dioxide gas produced Which experiment better represents the Law of Conservation of Mass Circle one 1 2 4 Matching Match the scientist to their experiment and or contribution to the Modern Atomic Theory You can use more than one letter per match if needed 1 Ernest Rutherford A Used cathode tube experiments to measure effects of electric and magnetic fields on cathode rays electrons Robert Millikan J J Thompson James Chadwick B Conducted the oil drop experiment C Determined the mass of the electron D Developed the Plum Pudding model of the atom E Identified the nucleus of the atom F Identified the neutrons in the nucleus of the atom G Identified the charge to mass ratio of the electron e m 5 Fill in the chart below Number of protons Number of electrons Charge Recitation 2 2 1 6 Identify the element below and fill in the chart for the number of protons neutrons and electrons are found in each isotope 21 30 X3 27 13 7 Strontium in the natural environment Earth has an isotopic distribution indicated in the first table below A sample created in the laboratory was designed to have a different isotopic distribution than naturally occurring strontium Using the data in the second table below calculate the atomic mass of the lab sample of Strontium 20 36 2 Element X Protons Neutrons Electrons Atomic number Mass number Recitation 2 Natural Strontium Isotope Exact Mass amu Percent Abundance 84Sr 86Sr 87Sr 88Sr 84Sr 86Sr 87Sr 88Sr 83 913 85 909 86 909 87 906 83 913 85 909 86 909 87 906 Lab sample Isotope Exact Mass amu Percent Abundance 0 56 9 86 7 00 82 58 52 00 28 00 8 00 12 00 3 The atomic mass of naturally occurring Sr is amu hint where can we find this The atomic mass of the Lab created sample of Sr is amu 8 The atomic mass of lutetium is 174 97 amu If lutetium has two isotopes Lu 175 and Lu 176 what are the percent abundances of each of these isotopes Fill in the table below Recitation 2 Isotope Exact Mass amu Percent Abundance 175Lu 176Lu 174 941 175 943 9 Classify each element as either a metal non metal or metalloid Element Metal Nonmetal Metalloid Element Metal Nonmetal Metalloid Aluminum Titanium Arsenic Copper Iron Phosphorus Oxygen Boron as a guide Mass in grams 10 Calculate and fill in the missing parts of the table below using the units in the column headers 32 4 g Carbon Mol atoms 4 22 mol of Copper 4 5 24 x 1024 atoms K 22 3 g of Cl2 mol of Cl2 atoms of Cl Recitation 2 5