What is a compound?
> An isolated atom has a net charge of .
> The tablecloth on my dining room table is 2 m long, which is cm or about in.
> The two most common elemental forms of carbon are diamond and .
> Most of the elements are solids at room temperature. Give three examples of elements that are liquids at room temperature, and three examples of elements that are gases at room temperature.
> If sodium chloride (table salt) is melted and then subjected to an electric current, elemental gas is produced, along with sodium metal.
> A simple way to generate elemental hydrogen gas is to pass through water.
> Give three examples of gaseous elements that exist as diatomic molecules. Give three examples of gaseous elements that exist as monatomic species.
> Molecules of nitrogen gas and oxygen gas are said to be , which means they consist of pairs of atoms.
> Why are the elements of Group 8 referred to as the noble or inert gas elements?
> The noble gas present in relatively large concentrations in the atmosphere is .
> Are most of the chemical elements found in nature in the elemental form or combined in compounds? Why?
> Most substances are composed of rather than elemental substances.
> The GPS in my car indicates that I have 100. mi left until I reach my destination. What is this distance in kilometers?
> The “Chemistry in Focus” segment Putting the Brakes on Arsenic discusses the dangers of arsenic and a possible help against arsenic pollution. Is arsenic a metal, a nonmetal, or a metalloid? What other elements are in the same group on the periodic table
> For each of the following elements, use the periodic table shown in Fig. 4.9 to give the chemical symbol, atomic number, and group number and to specify whether each element is a metal, nonmetal, or metalloid. a. strontium b. iodine c. silicon d. ces
> Without looking at your textbook or the periodic table, name three elements in each of the following groups (families). a. halogens b. alkali metals c. alkaline earth metals d. noble/inert gases
> Write the number and name (if any) of the group (family) to which each of the following elements belongs. a. cesium b. Ra c. Rn d. chlorine e. strontium f. Xe g. Rb
> The elements that lie close to the “stair-step” line as shown below in blue are called . Nonmetals Metals
> List five nonmetallic elements that exist as gaseous substances under ordinary conditions. Do any metallic elements ordinarily occur as gases?
> Most, but not all, metallic elements are solids under ordinary laboratory conditions. Which metallic elements are not solids?
> Where are the metallic elements found on the periodic table? Are there more metallic elements or nonmetallic elements?
> List the characteristic physical properties that distinguish the metallic elements from the nonmetallic elements.
> In which direction on the periodic table, horizontal or vertical, are elements with similar chemical properties aligned? What are families of elements with similar chemical properties called?
> The road sign I just passed says “New York City 100 km,” which is about mi.
> True or false? The elements are arranged in the periodic table in order of increasing mass.
> Complete the following table. Atomic Mass Number of Name Symbol Number Number Neutrons 8 10 20 iron 56 244 94 2Pu Hg 80 cobalt 59 28 56 chromium 26 -||
> Read the “Chemistry in Focus” segment Isotope Tales. Define the term isotope, and explain how isotopes can be used to answer scientific and historical questions.
> Read the “Chemistry in Focus” segment “Whair” Do You Live? How can isotopes be used to identify the general region of a person’s place of residence?
> How many protons and neutrons are contained in the nucleus of each of the following atoms? Assuming each atom is uncharged, how many electrons are present? 130 Ba a. 46 22 Ti 48 TI e. Li f. ĮLi с. b. 136 S6 Ba d. Ti 22
> Write the atomic symbol for each of the isotopes described below. a. Z = 26, A = 54 b. the isotope of iron with 30 neutrons c. number of protons = 26, number of neutrons = 31 d. the isotope of nitrogen with 7 neutrons e. Z = 7, A = 15 f. atomic num
> Write the atomic symbol / for each of the isotopes described below. a. the isotope of carbon with 7 neutrons b. the isotope of carbon with 6 neutrons c. Z = 6, number of neutrons = 8 d. atomic number 5, mass number 11 e. number of protons = 5, numbe
> For each of the following elements, use the periodic table shown in Fig. 4.9 to write the element’s atomic number, symbol, or name. Atomic Number Symbol Name 8 Cu 78 phosphorus 17 Sn zinc
> Which scientist discovered that the nuclei of most atoms contain neutrons as well as protons?
> Why do we not necessarily expect the number of neutrons in the nucleus of an atom to be the same as the number of protons?
> Students often have trouble relating measurements in the metric system to the English system they have grown up with. Give the approximate English system equivalents for each of the following metric system descriptions in Exercises 17–20. I need some 2.5
> What is the chief factor that determines the physical state of a sample of matter?
> For an isolated atom, why do we expect the number of electrons present in the atom to be the same as the number of protons in the nucleus of the atom?
> True or false? The mass number of a nucleus represents the number of protons in the nucleus.
> Explain what we mean when we say that a particular element consists of several isotopes.
> Which particles in an atom are most responsible for the chemical properties of the atom? Where are these particles located in the atom?
> An average atomic nucleus has a diameter of about m.
> The proton and the (electron/neutron) have almost equal masses. The proton and the (electron/neutron) have charges that are equal in magnitude but opposite in nature.
> What are the positively charged particles found in the nuclei of atoms called?
> Where are neutrons found in an atom? Are neutrons positively charged, negatively charged, or electrically uncharged?
> True or false? Rutherford’s bombardment experiments with metal foil suggested that the a particles were being deflected by coming near a large, positively charged atomic nucleus. h+
> Based on the following word descriptions, write the formula for each of the indicated substances. a. a compound whose molecules contain twice as many oxygen atoms as carbon atoms b. a compound whose molecules contain an equal number of carbon and oxyge
> Students often have trouble relating measurements in the metric system to the English system they have grown up with. Give the approximate English system equivalents for each of the following metric system descriptions in Exercises 17–20. The gas tank in
> Based on the following word descriptions, write the formula for each of the indicated substances. a. a compound whose molecules each contain six carbon atoms and six hydrogen atoms b. an aluminum compound in which there are three chlorine atoms for eac
> Find the symbol in Column 2 for each name in Column 1. Column 1 Column 2 1. Si 2. So 3. S a. helium b. sodium c. silver d. sulfur e. bromine f. potassium 4. Не 5. С 6. Co 7. Ва g. neon h. barium 8. Br 9. K i. cobalt j. carbon 10. Ро 11. Na 12. Ag 13.
> Several elements have chemical symbols beginning with the letter N. For each of the following chemical symbols, give the name of the corresponding element. a. Ne b. Ni c. N d. No e. Np f. Nb g. Nd
> A given compound always contains the same proportion (by mass) of the elements. This principle became known as .
> Which of the following describes a physical change? a. Paper is torn into several smaller pieces. b. Two clear solutions are mixed together to produce a yellow solid. c. A match burns in the air. d. Sugar is dissolved in water.
> Which of the following describes a chemical property? a. The density of iron is 7.87 g/cm3. b. A platinum wire glows red when heated. c. An iron bar rusts. d. Aluminum is a silver-colored metal.
> Matter in the state has no shape and fills completely whatever container holds it.
> Distillation and filtration are important methods for separating the components of mixtures. Suppose we had a mixture of sand, salt, and water. Describe how filtration and distillation could be used sequentially to separate this mixture into the three se
> True or false? Mixtures always result in a chemical reaction because they consist of two or more substances and thus combine to create a new product.
> Students often have trouble relating measurements in the metric system to the English system they have grown up with. Give the approximate English system equivalents for each of the following metric system descriptions in Exercises 17–20. My recipe for c
> Classify the following mixtures as homogeneous or heterogeneous. a. potting soil b. white wine c. your sock drawer d. window glass e. granite
> Solutions containing nickel(II) ion are usually bright green in color. When potassium hydroxide is added to such a nickel(II) solution, a pale-green fluffy solid forms and settles out of the solution. The fact that a solution of nickel(II) ion is bright
> Solutions containing nickel(II) ion are usually bright green in color. When potassium hydroxide is added to such a nickel(II) solution, a pale-green fluffy solid forms and settles out of the solution. The fact that a reaction takes place when potassium
> The fact that solutions of potassium chromate are bright yellow is an example of a property.
> True or false? Salad dressing (such as oil and vinegar dressing) separating into layers after standing is an example of a chemical change because the end result looks different from how it started. Explain your answer.
> Discuss the similarities and differences between a liquid and a gas.
> During a very cold winter, the temperature may remain below freezing for extended periods. However, fallen snow can still disappear, even though it cannot melt. This is possible because a solid can vaporize directly, without passing through the liquid st
> has a definite volume but takes the shape of its container.
> If a piece of hard, white blackboard chalk is heated strongly in a flame, the mass of the piece of chalk will decrease, and eventually the chalk will crumble into a fine white dust. Does this change suggest that the chalk is composed of an element or a c
> Classify each of the following as a(n) element, compound, pure substance, homogeneous mixture, and/or heterogeneous mixture. More than one classification is possible, and not all of them may be used. a. calcium carbonate (CaCO3) b. iron c. water you re
> Students often have trouble relating measurements in the metric system to the English system they have grown up with. Give the approximate English system equivalents for each of the following metric system descriptions in Exercises 17–20. My new kitchen
> If powdered elemental zinc and powdered elemental sulfur are poured into a metal beaker and then heated strongly, a very vigorous chemical reaction takes place, and the zinc sulfide is formed.
> During a filtration or distillation experiment, we separate a mixture into its individual components. Do the chemical identities of the components of the mixture change during such a process? Explain.
> Describe how the process of distillation could be used to separate a solution into its component substances. Give an example.
> The radius of a neon atom is 69 pm, and its mass is 3.35 3 10223 g. What is the density of the atom in grams per cubic centimeter (g/cm3)? Assume the atom is a sphere with volume=4/3πr3.
> The density of osmium (the densest metal) is 22.57 g/cm3. What is the mass of a block of osmium with dimensions 1.84 cm * 3.61 cm * 2.10 cm?
> The hottest temperature recorded in the United States is 134 °F in Greenland Ranch, California. The melting point of phosphorus is 44 °C. At this temperature, would phosphorus be a liquid or a solid?
> A friend tells you that it is 69.1 °F outside. What is this temperature in Celsius?
> Secretariat is known as the horse with the fastest run in the Kentucky Derby. If Secretariat’s record 1.25-mi run lasted 1 minute 59.2 seconds, what was his average speed in m/s?
> The longest river in the world is the Nile River with a length of 4145 mi. How long is the Nile in cable lengths, meters, and nautical miles? Use these exact conversions to help solve the problem: 6 ft = 1 fathom 100 fathoms = 1 cable length 10 cable l
> For each of the mathematical expressions given: a. Tell the correct number of significant figures for the answer. b. Evaluate the mathematical expression using correct significant figures in the result. Number of Significant Figures Result 0.0394 x
> Give the metric prefix that corresponds to each of the following: a. 1000 b. 10-3 c. 10-9 d. 1,000,000 e. 10-1 f. 10-6
> Complete the following table: Number of Significant Figures Number Exponential Notation 900.0 3007 23,450 270.0 437,000
> The “Chemistry in Focus” segment Measurement: Past, Present, and Future states that hormones can be detected to a level of 1028 g/L. Convert this level to units of pounds per gallon.
> Read the “Chemistry in Focus” segment Concrete—An Ancient Material Made New and classify concrete as an element, a mixture, or a compound. Defend your answer.
> Of the three states of matter, and are not very compressible.
> For each of the following descriptions, identify the power of 10 being indicated by the prefix in the measurement. a. The sign on the interstate highway says to tune my AM radio to 540 kilohertz for traffic information. b. My new digital camera has a 2
> Convert the following temperatures to Fahrenheit degrees. a. 25 °C b. 273 K d. 0 K c. 2196 °C e. 86 °C f. 2273 °C
> A sample containing 33.42 g of metal pellets is poured into a graduated cylinder initially containing 12.7 mL of water, causing the water level in the cylinder to rise to 21.6 mL. Calculate the density of the metal.
> A solid metal sphere has a volume of 4.2 ft3. The mass of the sphere is 155 lb. Find the density of the metal sphere in grams per cubic centimeter.
> An organic solvent has a density of 1.31 g/mL. What volume is occupied by 50.0 g of the liquid?
> A sample of a liquid solvent has a density of 0.915 g/mL. What is the mass of 85.5 mL of the liquid?
> What are the fundamental units of mass, length, and temperature in the metric system?
> Classify the following as mixtures or pure substances. a. the vegetable soup you had for lunch b. the fertilizer your dad spreads on the front lawn in the spring c. the salt you sprinkle on your French fries d. the hydrogen peroxide you cleaned a cut
> Carry out the indicated temperature conversions. a. 175 °F to kelvins b. 255 K to Celsius degrees c. 245 °F to Celsius degrees d. 125 °C to Fahrenheit degrees
> Convert the following temperatures to kelvins. a. 0 °C b. 25 °C c. 37 °C d. 100 °C e. 2175 °C f. 212 °C
> Given that one metric ton = 1000 kg, how many metric tons are in 5.3 3 103 lb?
> The mean distance from the earth to the sun is 9.3 3 107 mi. What is this distance in kilometers? in centimeters?
> Perform each of the following conversions, being sure to set up clearly the appropriate conversion factor(s) in each case. a. 908 oz to kilograms b. 12.8 L to gallons c. 125 mL to quarts d. 2.89 gal to milliliters e. 4.48 lb to grams f. 550 mL to q
> Which of the following substances is(are) homogeneous mixture(s)? a. chocolate chip cookie b. iodine crystals (I2) c. air (in this room) d. gasoline (for a car) e. sucrose, C12H22O11 (commonly found in table sugar)
> A rectangular solid measures 1.0 m by 2.4 mm by 3.9 dm. What is the volume in liters?
> Given that 1 L = 1000 cm3, determine what conversion factor is appropriate to convert 350 cm3 to liters; to convert 0.200 L to cubic centimeters.
> What does it mean to say that a solution is a homogeneous mixture?
