Chapter 6

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(1) 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 $$ a.[\mathrm{Ne}] 3 \mathrm{s}^{2} \quad b. [\mathrm{He}] 2 \mathrm{s}^{2} \quad c. [\mathrm{Kr}] 5 \mathrm{s}^{2}4 \mathrm {d}^{10} 5 \mathrm{p}^{5}$$

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.

\begin{equation} \begin{array}{l}{\text { Determine in which block of the periodic table are the elements having the }} \\ {\text { following valence electron configurations. }}\end{array} \end{equation} $${ a. }s^{2} p^{4} \quad \quad \text { b. }s^{1}\quad \quad{ c. }\mathrm{s}^{2} \mathrm{d}^{1} \quad \quad \text { d. } \mathrm{s}^{2} \mathrm{p}^{1}$$

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 \(\mathrm{f}\) -blocks.

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

Challenge Determine which element in each pair has the largest atomic radius: \begin{equation} \begin{array}{l}{\text { a. the element in period } 2, \text { group } 1 ; \text { or the element in period } 3, \text { group } 18} \\ {\text { b. the element in period } 5, \text { group } 2 ; \text { or the element in period } 3, \text { group } 16} \\ {\text { c. the element in period } 3, \text { group } 14 ; \text { or the element in period } 6, \text { group } 15} \\\ {\text { d. the element in period } 4, \text { group } 18 ; \text { or the element in period } 2, \text { group } 16}\end{array} \end{equation}

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. \(\begin{array}{ll}{\text { a. electronegativity }} & {\text { c. atomic radius }} \\ {\text { b. ionic radius }} & {\text { d. ionization energy }}\end{array}\)

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.

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 Mendeleev's periodic table was in error.

Explain the contribution of Newlands's 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. \(\begin{array}{ll}{\text { a. oxygen }} & {\text { c. germanium }} \\ {\text { b. barium }} & {\text { d. iron }}\end{array}\)

Match each item on the left with its corresponding group on the right. Identify each of the following as a metal, a nonmetal, or a metalloid. \(\begin{array}{ll}{\text { a. alkali metals }} & {\text { 1. group } 18} \\\ {\text { b. halogens }} & {\text { 2. group } 1} \\ {\text { c. alkaline earth metals }} & {\text { 3. group } 2} \\ {\text { d. noble gases }} & {\text { 4. group } 17}\end{array}\)

Sketch a simplified periodic table, and use labels to iden- tify the alkali metals, alkaline earth metals, transition metals, inner transition metals, noble gases, and halogens.

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

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?

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

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 atom's 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?

Explain how an atom's valence electron configuration determines its place in the periodic table.

Write the electron configuration for the element fitting each of the following descriptions. \(\begin{array}{l}{\text { a. the metal in group } 15 \text { that is part of compounds often }} \\ {\text { found in cosmetics }} \\ {\text { b. the halogen in period } 3 \text { that is part of a bleaching }} \\ {\text { compound used in paper production }} \\ {\text { c. the transition metal that is a liquid at room tempera- }} \\ {\text { ture; is sometimes used in outdoor security lights }}\end{array}\)

Determine the group, period, and block in which each of the following elements is located in the periodic table. \(\begin{array}{ll}{\text { a. }[\mathrm{Kr}] 5 s 2^{4} \mathrm{d}^{1}} & {\text { c. }[\mathrm{He}] 2 \mathrm{s}^{2} 2 \mathrm{p}^{6}} \\ {\text { b. }[\mathrm{Ar}] 4 \mathrm{s}^{2} 3 \mathrm{d}^{10} 4 \mathrm{p}^{3}} & {\text { d. }[\mathrm{Ne}] 3 \mathrm{s}^{2} 3 \mathrm{p}^{1}}\end{array}\)

\begin{equation} \begin{array}{l}{\text { Given any two elements within a group, is the element }} \\ {\text { with the larger atomic number likely to have a larger or }} \\\ {\text { smaller atomic radius than the other element? }}\end{array} \end{equation}

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?

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 light-weight. 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 \([\mathrm{Ne}] 3 \mathrm{s}^{2} 3 \mathrm{p}^{1} .\) Identify the metal and give its group, period, and block.

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?