1) Circle any of the following that are most likely a pure substances? A) T-shirt B) sand C) air D) cherry tree E) tap water F) None of these 2) Which one of the following is often easily separated into its components by simple techniques such as filtering or decanting? A) homogeneous mixture B) compounds C) heterogeneous mixture D) elements E) solutions 3) In the following list, only is not an example of a chemical reaction. A) burning a plastic water bottle B) the production of hydrogen gas from water C) the tarnishing of a copper penny D) ethanol evaporating E) acid burning your skin 4) Precision refers to . A) how close a measured number is to other measured numbers B) how close a measured number is to the true value C) how close a measured number is to the calculated value D) how close a measured number is to zero E) how close a measured number is to infinity 5) The number with the most significant zeros is: A) 0.00000002510 B) 0.025000001 C) 250000001 D) 2.501 × 10^-7 E) 2.5100000 6) If matter is uniform throughout and cannot be separated into other substances by physical processes, but can be decomposed into other substances by chemical processes, it is called a(n): A) heterogeneous mixture B) compound C) homogeneous mixture D) element E) mixture of elements 7) A package of Aluminum foil contains 50 ft^2 of foil, which weighs approximately 240.0 grams. Aluminum has a density of 2.70 g/cm^3. What is the approximate thickness of the foil? 8) Name one metalloid in period 4 and one non-metal in period 5: 9) A 4.369 g sample of metal is placed in a flask that has 124.8 mL of water in it. After adding the metal, the new volume of water plus the metal is 126.9 mL. If the density of water is 1.000 g/mL, the density of the solid is g/cm^3. 10) If a car’s speed is 40.0 km/hr, what is its speed in inches/sec? (2.54 cm = 1 inch) 11) The density of air under ordinary conditions at 25 °C is 1.19 g/L. How many kilograms of air are in a room that measures 13.0 ft × 12.0 ft and has a 9.0 ft ceiling? 12) Write the symbols for the Nitrite ion and for aluminum sulfate: 13) Silver has two naturally occurring isotopes with the following isotopic masses: 107 Ag 109 Ag 106.90509 108.9047 The average atomic mass of silver is 107.8682 amu. Calculate the abundance of the lighter of the two isotopes? (Hint: Abundance 107 + Abundance 109 = 1.00) 14) Which one of the following species has as many electrons as it has neutrons? A) 1H B) 40Ca2+ C) 14C D) 19F - E) 14C2+ 15) Which formula/name pair is incorrect? A) FeSO4 iron(II) sulfate B) Fe2(SO3)3 iron(III) sulfite C) FeS iron(II) sulfide D) FeSO3 iron(II) sulfite E) Fe2(SO4)3 iron(III) sulfide 16) Elements in Group 7A are known as the . A) alkaline earth metals B) alkali metals C) chalcogens D) halogens E) noble gases 17) Write the formulas of Calcium Nitride and Ammonium Carbonate: 18) Calcium reacts with a certain nonmetallic element to form a compound with the general formula CaX. Element X is a diatomic gas at room temperature. Element X must be . 19) Write the names for MnS and ZnSO3 : 20) Write the names for Mg(ClO3)2 and Na3N: 22) What is the molecular formula for 1-propanol? 23) How many electrons are there in one atom of 71Ga? 24) Which pair of atoms constitutes a pair of isotopes of the same element? 25) An ion has 23 protons, 27 neutrons, and 19 electrons. The complete symbol for the ion is: