Question: For each of the following elements, use

> Why must the total number of positive charges in an ionic compound equal the total number of negative charges?

> Why does an ionic compound conduct an electric current when the compound is melted but not when it is in the solid state?

> Why does a solution of sodium chloride in water conduct an electric current?

> List some properties of a substance that would lead you to believe it consists of ions. How do these properties differ from those of nonionic compounds? Source of electric power Salt dissolved in water

> On the basis of the element’s location in the periodic table, indicate what simple ion each of the following elements is most likely to form. a. P b. Ra c. At d. Rn e. Cs f. Se

> For each of the following atomic numbers, use the periodic table to write the formula (including the charge) for the simple ion that the element is most likely to form. a. 53 b. 38 c. 55 d. 88 e. 9 f. 13

> For the following ions, indicate whether electrons must be gained or lost from the parent neutral atom, and how many electrons must be gained or lost. a. O2+ b. P3- c. Cr3+ d. Sn2+ e. Rb+ f. Pb2+

> For the following processes that show the formation of ions, use the periodic table to indicate the number of electrons and protons present in both the ion and the neutral atom from which the ion is made. а. Са — Са?+ + 2e- b. Р+ Зе-— р3- Br- с. Br

> Who is taller, a man who is 1.62 m tall or a woman who is 5 ft 6 in. tall?

> State the number of protons, electrons, and neutrons for /

> How many electrons are present in each of the following ions? a. Ba+2 b. P3- c. Mn2+ d. Mg2+ e. Cs+ f. Pb2-

> True or false? N-3 and P-3 contain a different number of protons but the same number of electrons. Justify your answer.

> Based on their location in the periodic table, give the symbols for three elements that would be expected to form positive ions in their reactions.

> Simple negative ions formed from single atoms are given names that end in .

> Positive ions are called , whereas negative ions are called .

> An ion that has two more electrons outside the nucleus than there are protons in the nucleus will have a charge of .

> A simple ion with a 3+ charge (for example, Al+3) results when an atom (gains/loses) electrons.

> Ions are produced when an atom gains or loses .

> 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

> 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.

> What is a compound?

> 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.