Name Pre-AP Chemistry: Worksheet # 3.4 Class Period Date Directions: Write your answers to the following questions in the space provided. For problem solving, all of the work leading up to the final answer must be shown in order to receive credit. You will not receive credit for “Magic 1. Use the periodic table to separate these 12 elements into six pairs of elements having similar properties. Ca, K, Ga, P, Si, Rb, B, Sr, Sn, Cl, Bi, Br Ca & Sr K & Rb Ga & B P & Bi Si & Sn Cl & Br 2. Use the periodic table to identify by name and symbol the elements that have the following locations. 3. a. Group 15, Period 3 b. Groups 2, Period 6 Phosphorus Barium Where are the metals usually found on the periodic table? Where are the nonmetals found? The metalloids? Metals are on the left side and in the center; nonmetals are in the upper-right corner; metalloids form a border between the metals and nonmetals. 4. What are the major differences in the physical properties of metals, nonmetals, and metalloids? Metals—have luster, are malleable and ductile, good conductors of heat and electricity Nonmetals—are dull, not good conductors of heat and electricity, are brittle Metalloids—tend to be brittle, are semiconductors of heat and electricitiy 5. List one distinctive characteristic for the halogens, one for the noble gases, and one for the alkali metals. The halogens are the most reactive nonmetals The noble gases are unreactive. The alkali metals are the most reactive metals. 6. Hydrogen is shown on some periodic tables in two places: both with the alkali metals and with the halogens. What does this indicate about the characteristics of hydrogen? This indicates that hydrogen has properties similar to the alkali metals to the halogens. 1 7. Many people who have high blood pressure have been advised by their doctors to reduce their intake of sodium. Therefore, it is recommended that these individuals try to eliminate table salt (NaCl), a primary source of sodium, from their diets. Another salt, potassium chloride, may be safely substituted by those who still desire the flavor enhancement provided by salt. What evidence do you have that its properties are similar to the properties of sodium chloride? Both sodium and potassium are in the first group of the periodic table and elements in the same of group on the periodic table have similar chemical properties. 8. Identify the classes of elements to which each of the following elements belongs. Each element is described by more than one term. Choose from the following classes: metal, nonmetal, metalloid; alkali metal, alkaline earth metal, transition metal, inner transition metal (lanthanide or actinide), halogen, noble gas; solid, liquid, gas (at room temperature). ex. argon: nonmetal, noble gas, gas a. helium: b. einsteinium: c. calcium: d. sulfur: e. silicon: f. cesium: g. platinum: h. bromine: i. 9. nitrogen: Nonmetal Noble gas Gas Metal Inner Transition Metal Solid Metal Alkaline Earth Metal Solid Nonmetal Oxygen Group Solid Metalloid Carbon Group Solid Metal Alkali Metal Solid Metal Transition Metal Solid Nonmetal Halogen Liquid Nonmetal Nitrogen Group Gas Name a chemical or physical property that will distinguish between the following pairs of elements. a. Sodium and silver: Sodium is more reactive in water than silver. b. Oxygen and helium: Oxygen promotes combustion. Oxygen is less dense than helium. c. Mercury and gallium: Mercury is a liquid. Gallium is a solid 2 10. Your spaceship lands on an unexplored planet. Initial surveys of the terrain result in the discovery of the presence of three elements: X, Y and Z (not real chemical symbols). One of these elements is a colorless gas at room temperature. All three tend to exist as diatomic molecules (two atoms joined to form a molecule) in elemental form. While their densities and boiling point vary widely, all three react readily with sodium to form compounds of the formulas NaX, NaY and NaZ. As a research scientist on the spaceship crew, it is your responsibility to decide whether these elements should be grouped together on a table of elements. What is your decision? What evidence do you have in support of your decision? These elements should be grouped with the halogens because they combine in a one to one ratio with sodium, an alkali metal. 3