Challenge Determine which element in each pair has the

Describe the development of the modern periodic table. Include contributions made by Lavoisier, Newlands, Mendeleev, and Moseley

Sketch a simplified version of the periodic table, and indicate the location of metals, nonmetals, and metalloids.

Describe the general characteristics of metals, nonmetals, and metalloids

Identify each of the following as a representative element or a transition element. a. lithium (Li) b. platinum (Pt) c. promethium (Pm) d. carbon (C)

Compare For each of the given elements, list two other elements with similar chemical properties. a. iodine (I) b. barium (Ba) c. iron (Fe)

Compare According to the periodic table, which two elements have an atomic mass less than twice their atomic number?

Interpret Data A company plans to make an electronic device. They need to use an element that has chemical behavior similar to that of silicon (Si) and lead (Pb). The element must have an atomic mass greater than that of sulfur (S), but less than that of cadmium (Cd). Use the periodic table to determine which element the company could use

Without using the periodic table, determine the group, period, and block of an atom with the following electron configurations. a. [Ne]3 s 2 b. [He]2 s 2 c. [Kr]5 s 24 d 105 p 5

What are the symbols for the elements with the following valence electron configurations? a. s 2d 1 b. s 2p 3 c. s 2p

Challenge Write the electron configuration of the following elements. a. the group 2 element in the fourth period c. the noble gas in the fifth period b. the group 12 element in the fourth period d. the group 16 element in the second period

Explain what determines the blocks in the periodic table.

Determine in which block of the periodic table are the elements having the following valence electron configurations. a. s 2 p 4 b. s 1 c. s 2 d 1 d. s 2 p

Infer Xenon, a nonreactive gas used in strobe lights, is a poor conductor of heat and electricity. Would you expect xenon to be a metal, a nonmetal, or a metalloid? Where would you expect it to be on the periodic table? Explain.

Explain why elements within a group have similar chemical properties

Model Make a simplified sketch of the periodic table, and label the s-, p-, d-, and f-blocks

Which has the largest atomic radius: magnesium (Mg), silicon (Si), sulfur (S), or sodium (Na)? The smallest?

The figure on the right shows helium, krypton, and radon. Which one is krypton? How can you tell?

Can you determine which of two unknown elements has the larger radius if the only known information is that the atomic number of one of the elements is 20 greater than the other? Explain.

Challenge Determine which element in each pair has the largest atomic radius: a. the element in period 2, group 1; or the element in period 3, group 18 b. the element in period 5, group 2; or the element in period 3, group 16 c. the element in period 3, group 14; or the element in period 6, group 15 d. the element in period 4, group 18; or the element in period 2, group 16

Explain how the period and group trends in atomic radii are related to electron configuration

Indicate whether fluorine or bromine has a larger value for each of the following properties. a. electronegativity c. atomic radius b. ionic radius d. ionization energy

Explain why it takes more energy to remove the second electron from a lithium atom than it does to remove the fourth electron from a carbon atom.

Calculate Determine the differences in electronegativity, ionic radius, atomic radius, and first ionization energy for oxygen and beryllium

Make and Use Graphs Graph the atomic radii of the representative elements in periods 2, 3, and 4 versus their atomic numbers. Connect the points of elements in each period, so that there are three separate curves on the graph. Summarize the trends in atomic radii shown on your graph. Explain.

Explain how Mendeleevs periodic table was in error.

Explain the contribution of Newlandss law of octaves to the development of the modern periodic table.

Lothar Meyer and Dmitri Mendeleev both proposed similar periodic tables in 1869. Why is Mendeleev generally given credit for the periodic table?

What is the periodic law?

Describe the general characteristics of metals

What are the general properties of a metalloid?

Identify each of the following as a metal, a nonmetal, or a metalloid. a. oxygen c. germanium b. barium d. iron

Match each item on the left with its corresponding group on the right. a. alkali metals 1. group 18 b. halogens 2. group 1 c. alkaline earth metals 3. group 2 d. noble gases 4. group 17

Sketch a simplified periodic table, and use labels to identify the alkali metals, alkaline earth metals, transition metals, inner transition metals, noble gases, and halogens. Actinium 89 Ac (227) Rutherfordium 104 Rf (261) Lanthanum 57 La 138.906 Hafnium 72 Hf 178.49 Figure 6.19

Explain what the dark line running down the middle of Figure 6.19 indicates.

Give the chemical symbol of each of the following elements. a. a metal used in thermometers b. a radioactive gas used to predict earthquakes; the noble gas with the greatest atomic mass c. a coating for food cans; it is the metal in group 14 with the lowest atomic mass d. an inner transition metal that is used to make burglar-proof vaults; also the name of a coin

If a new halogen and a new noble gas were discovered, what would be their atomic numbers?

If the periodic table were arranged by atomic mass, which of the first 55 elements would be ordered differently than they are in the existing table?

New Heavy Element If scientists discovered an element with 117 protons, what would be the its group and period? Would it be a metal, a metalloid, or a nonmetal?

Naming New Elements Recently discovered elements that have not been fully verified are given temporary names using the prefixe words in Table 6.6. Based on this system, write names for elements 117 to 120. Table 6.6 Prefixes 01234 nil un b(i) tr(i) quad 56789 pent hex sept oct en(n)

Give the chemical symbol for each element. a. the element in period 3 that can be used in making computer chips because it is a metalloid b. the group 13, period 5 metal used in making flat screens for televisions c. an element used as a filament in lightbulbs; has the highest atomic mass natural elements in group 6

Household Products Why do the elements chlorine, used in laundry bleach, and iodine, a nutrient added to table salt, have similar chemical properties?

How is the energy level of an atoms valence electrons related to its period in the periodic table?

How many valence electrons does each noble gas have?

What are the four blocks of the periodic table?

What electron configuration has the greatest stability?

Explain how an atoms valence electron configuration determines its place in the periodic table.

Write the electron configuration for the element fitting each of the following descriptions. a. the metal in group 15 that is part of compounds often found in cosmetics b. the halogen in period 3 that is part of a bleaching compound used in paper production c. the transition metal that is a liquid at room temperature; is sometimes used in outdoor security lights

Determine the group, period, and block in which each of the following elements is located in the periodic table. a. [Kr]5s 2 4 d 1 c. [He]2 s 2 2 p 6 b. [Ar]4 s 2 3 d 10 4 p 3 d. [Ne]3 s 2 3 p 1

Given any two elements within a group, is the element with the larger atomic number likely to have a larger or smaller atomic radius than the other element?

Table 6.7 shows the number of elements in the first five periods of the periodic table. Explain why some of the periods have different numbers of elements. Table 6.7 Number of Elements in Periods 15 Period 123 45 Number of elements 2 8 8 18 18

Coins One of the transition groups is often called the coinage group because at one time many coins are made of these metals. Which group is this? What elements in this group is still used in many U.S. coins today?

Do any of the halogens have their valence electrons in orbitals of the same energy level? Explain.

The transition elements have their valence electrons in orbitals of more than one energy level, but the representative elements have their valence electrons in orbitals of only one energy level. Show this by using the electron configurations of a transition element and a representative element as examples

Fireworks Barium is a metal that gives a green color to fireworks. Write the electron configuration for barium. Classify it according to group, period, and block in the periodic table

Headphones Neodymium magnets can be used in stereo headphones because they are powerful and lightweight. Write the electron configuration for neodymium. In which block of the periodic table is it?

Soda Cans The metal used to make soda cans has the electron configuration [Ne]3 s 2 3 p 1 . Identify the metal and give its group, period, and block.

Identify each missing part of Table 6.8. Table 6.8 Electron Configuration Period Group Element Electron Configuration 3 Mg [Ne]3 s 2 4 14 Ge 12 Cd [Kr]5 s 2 4 d 10 2 1 [He]2 s

What is ionization energy?

An element forms a negative ion when ionized. On what side of the periodic table is the element located? Explain.

Of the elements magnesium, calcium, and barium, which forms the ion with the largest radius? The smallest? What periodic trend explains this?

Explain why each successive ionization of an electron requires a greater amount of energy.

How does the ionic radius of a nonmetal compare with its atomic radius? Explain the change in radius.

Explain why atomic radii decrease as you move from left to right across a period.

Which element has the larger ionization energy? a. Li, N b. Kr, Ne c. Cs, Li

Explain the octet rule. Why are hydrogen and helium exceptions to the octet rule? A B Figure 6.20

Use Figure 6.20 to answer each of the following questions. Explain your reasoning for each answer. a. If A is an ion and B is an atom of the same element, is the ion a positive or negative ion? b. If A and B represent the atomic radii of two elements in the same period, what is their order? c. If A and B represent the ionic radii of two elements in the same group, what is their order?

How many valence electrons do elements in group 1 have? In group 18? a b Figure 6.21

Figure 6.21 shows two ways to define an atomic radius. Describe each method. When is each method used?

Chlorine The electron configuration of a chlorine atom is [Ne]3 s 2 3 p 5 . When it gains an electron and becomes an ion, its electron configuration changes to [Ne]3 s 2 3 p 6 , or [Ar], the electron configuration for argon. Has the chlorine atom changed to an argon atom? Explain.

Sport Bottles Some sports bottles are made of Lexan, a plastic containing a compound of the elements chlorine, carbon, and oxygen. Order these elements from greatest to least according to atomic radius and ionic radius

Contact Lenses Soft contact lenses are made of silicon and oxygen atoms bonded together. Create a table listing the atomic and ionic electron configurations, and the atomic and ionic radii for silicon and oxygen. When silicon bonds with oxygen, which atoms become larger and which become smaller? Why?

Artificial Sweetener Some diet sodas contain the artificial sweetener aspartame, a compound containing carbon, nitrogen, oxygen, and other atoms. Create a table showing the atomic and ionic radii of carbon, nitrogen, and oxygen. (Assume the ionization states shown in Figure 6.14.) Use the table to predict whether the sizes of carbon, nitrogen, and oxygen atoms increase or decrease in size when they form bonds in aspartame.

Define an ion.

Explain why the radius of an atom cannot be measured directly.

What is the metalloid in period 2 of the periodic table that is part of compounds used as water softeners?

Do you expect cesium, a group 1 element used in infrared lamps, or bromine, a halogen used in firefighting compounds to have the greatest electronegativity? Why? A C B D Figure 6.22

Figure 6.22 shows different sections of the periodic table. Give the name of each section, and explain what the elements in each section have in common.

Which element in each pair is more electronegative? a. K, As b. N, Sb c. Sr, Be

Explain why the s-block of the periodic table is twogroups wide, the p-block is six-groups wide, and the d-block is ten-groups wide.

Most of the atomic masses in Mendeleevs table are different from todays values. Explain why.

Arrange the elements oxygen, sulfur, tellurium, and selenium in order of increasing atomic radii. Is your order an example of a group trend or a period trend?

Milk The element with the electron configuration [Ar]4 s 2 is an important mineral in milk. Identify this elements group, period, and block in the periodic table.

Why are there no p-block elements in the first period?

Jewelry What are the two transition metals that are used in making jewelry and are the group 11 elements with the lowest atomic masses?

Which has the largest ionization energy, platinum, an element sometimes used in dental crowns, or cobalt, an element that provides a bright blue color to pottery?

Apply Sodium forms a 1+ ion, while fluorine forms a 1- ion. Write the electron configuration for each ion. Why dont these two elements form 2+ and 2- ions, respectively?

Make and Use Graphs The densities of the group 15 elements are given in Table 6.9. Plot density versus atomic number, and state any trends you observe. Table 6.9 Group 15 Density Data Element Atomic Number Density (g/ c m 3) Nitrogen 7 1.25 1 0 -3 Phosphorus 15 1.82 Arsenic 33 5.73 Antimony 51 6.70 Bismuth 83 9.78

Generalize The outer-electron configurations of elements in group 1 can be written as n s 1 , where n refers to the elements period and its principal energy level. Develop a similar notation for all the other groups of the representative elements

Identify A period 3 representative element is part of the rough material on the side of a match box used for lighting matches. Table 6.10 shows the ionization energies for this element. Use the information in the table to infer the identity of the element. Explain. Table 6.10 Ionization Energies in kJ/mol Number 1st 2nd 3rd 4th 5th 6th Ionization energy 1010 1905 2910 4957 6265 21,238

Interpret Data The melting points of the period 6 elements are plotted versus atomic number in Figure 6.23. Determine the trends in melting point and the orbital configurations of the elements. Form a hypothesis that explains the trends.

Ionization energies are expressed in kilojoules per mole, but the energy to remove an electron from a gaseous atom is expressed in joules. Use the values in Table 6.6 to calculate the energy, in joules, required to remove the first electron from an atom of Li, Be, B, and C. Then, use the relationship 1 eV = 1.60 1 0 -19 J to convert the values to electron volts.

Define matter. Identify whether or not each of the following is a form of matter. (Chapter 1) a. microwaves d. velocity b. helium inside a balloon e. a speck of dust c. heat from the Sun f. the color blue

Convert the following mass measurements as indicated. (Chapter 2) a. 1.1 cm to meters c. 11 mg to kilograms b. 76.2 pm to millimeters d. 7.23 g to kilograms

How is the energy of a quantum of emitted radiation related to the frequency of the radiation? (Chapter 5)

What element has the ground-state electron configuration of [Ar]4 s 2 3 d 6 ? (Chapter 5)

Triads In the early 1800s, German chemist J. W. Dobereiner proposed that some elements could be classified into sets of three, called triads. Research and write a report on Dobereiners triads. What elements comprised the triads? How were the properties of elements within a triad similar?

Affinity Electron affinity is another periodic property of the elements. Write a report on what electron affinity is, and describe its group and period trends.

Mendeleev placed the noble gases on the left of his table. Why does placement on the right of the modern table make more sense?

Which block on Mendeleevs table was most like todays placement? Which block was least like todays placement? Why?

Most of the atomic masses in Mendeleevs table differ from todays values. Why do you think this is so?