Chapter 9. Electronegativity and Chemical Bonding

In general, the formation of a bond between two or more atoms ______. (Select all that apply.) decreases both kinetic and potential energy increases the overall potential energy of the system lowers the potential energy between oppositely charge particles produces a more stable system

lowers the potential energy between oppositely charge particles produces a more stable system

In general, the formation of a bond between two or more atoms ______. (Select all that apply.) lowers the potential energy between oppositely charge particles decreases both kinetic and potential energy increases the overall potential energy of the system produces a more stable system

lowers the potential energy between oppositely charge particles produces a more stable system

A polar bond is a covalent bond in which there is an electronegativity difference between the two bonded atoms and electrons are shared unequally. The atom with the higher electronegativity will have a partial _____ charge and is marked with the symbol _____ while the atom with the lower electronegativity will have a partial _____ charge and is marked with the symbol _____.

negative; δ-, positive; δ+

When the elements Mg and Cl form an ionic bond, Mg loses --electron(s) from the 3s orbital to form the Mg2+ cation. Cl gains --electron(s) in the 3p orbital to form the Cl- anion. Since the total number of electrons lost always equals the total number of electrons gained, the compound formed will contain -- Mg2+ ion(s) for every -- Cl- ion(s). Fill in the blanks with the appropriate numbers.

2 1 1 2

Which of the following statements correctly describe a polar covalent bond? Select all that apply. A bond between atoms whose electronegativities differ by more than 0.4 but less than 1.7 is polar. In a polar covalent bond the electron density is highest over the more electronegative atom. A polar bond is a covalent bond in which electrons are shared equally. In a polar covalent bond the atom with the lower electronegativity is marked δ- because it has less electron density.

A bond between atoms whose electronegativities differ by more than 0.4 but less than 1.7 is polar. In a polar covalent bond the electron density is highest over the more electronegative atom.

Which option correctly describes the influence of electronegativity difference (ΔEN) on bond character? Select all that apply. A bond with ΔEN greater than 1.7 is considered to be mostly covalent. A bond with ΔEN of 0.4 or less is considered mostly covalent. A bond with ΔEN greater than 1.7 is considered to be mostly ionic. Any bond with ΔEN greater than 0.0 is considered to be polar.

A bond with ΔEN of 0.4 or less is considered mostly covalent. A bond with ΔEN greater than 1.7 is considered to be mostly ionic.

Using the table of electronegativity values provided, which of the following bonds are polar covalent? Select all that apply.

B-Cl C-N H-O

The bonding of chlorine with each of the Period 3 elements shows a change in bonding type from ionic through polar covalent to nonpolar covalent. Select the properties that reflect this change in bonding character. Electrical conductivity at the melting point is high only for chlorides of Group 1A(1) and Group 2A(2). At room temperature, the Period 3 covalently bonded molecules of chlorine are all liquids. Electron density relief maps show a steady increase in electron sharing from NaCl to Cl2. Melting point increases as the bonding character changes from ionic to covalent. There is a general decrease in ΔEN moving from left to right across the period.

Electrical conductivity at the melting point is high only for chlorides of Group 1A(1) and Group 2A(2). Electron density relief maps show a steady increase in electron sharing from NaCl to Cl2. There is a general decrease in ΔEN moving from left to right across the period.

Which of the following options correctly describe electronegativity? Select all that apply. The most electronegative element is hydrogen because it has the smallest atomic size. Electronegativity can be measured by measuring the energy changes when an atom gains an electron. Electronegativity measures the ability of an atom in a covalent bond to attract the shared electron pair(s). Electronegativity is another word for electron affinity. Electronegativity is a relative quantity.

Electronegativity measures the ability of an atom in a covalent bond to attract the shared electron pair(s). Electronegativity is a relative quantity.

Which of the following are characteristic properties of ionic compounds? Select all that apply. Hard but flexible High melting points Nonconductors in the solid state Nonconductors in aqueous solution

High melting points Nonconductors in the solid state

Why does an ionic solid not conduct electricity in the solid state but is a good conductor when melted or dissolved in water? Select all that apply. In the liquid or dissolved state, the ions can release electrons that cause a current to flow. In the solid state, the ions are held in specific positions and are not free to move. An ionic solid contains a metal, and metals conduct electricity. In the liquid or dissolved state, the ions are free to move and can carry an electric current.

In the solid state, the ions are held in specific positions and are not free to move. In the liquid or dissolved state, the ions are free to move and can carry an electric current.

Consider the formation of an ionic bond between the elements potassium (K) and chlorine (Cl). Which of the following statements describe this process correctly? Select all that apply. K loses one electron from its 4s orbital to form a K+ cation. Cl gains two electrons to form the Cl- anion. The formation of this bond requires two K atoms for every one Cl atom. Both the K+ and Cl- ions have full outer shells containing 8 electrons. The total number of electrons lost equals the total number of electrons gained.

K loses one electron from its 4s orbital to form a K+ cation. Both the K+ and Cl- ions have full outer shells containing 8 electrons. The total number of electrons lost equals the total number of electrons gained.

Which of the following options correctly describe the general trends in electronegativity? Select all that apply. Electronegativity tends to increase as atomic size increases. Metals tend to have lower electronegativities than nonmetals. Electronegativity tends to decrease down a group of the periodic table. Fluorine is the most electronegative element. Electronegativity tends to decrease from left to right across a period of the periodic table.

Metals tend to have lower electronegativities than nonmetals. Electronegativity tends to decrease down a group of the periodic table. Fluorine is the most electronegative element.

Which of the following statements correctly describe trends in lattice energy? Select all that apply. NaCl should have a higher lattice energy than Na2O. The lattice energy of an ionic compound decreases as the charges on the ions increase. NaCl is expected to have a higher lattice energy than NaBr. The lattice energy of an ionic compound tends to decrease as ionic size increases.

NaCl is expected to have a higher lattice energy than NaBr. The lattice energy of an ionic compound tends to decrease as ionic size increases.

Which of the following options describe how to draw the Lewis electron-dot symbol for a given element? Select all that apply. One dot is placed on each side of the element symbol before pairing any dots. The A-group number of the element gives the number of valence electrons. Dots are placed clockwise, starting at the top of the symbol. The Lewis symbol includes only the valence electrons for the element. Dots are placed initially in pairs on the sides of the element symbol to represent the valence electrons.

One dot is placed on each side of the element symbol before pairing any dots. The A-group number of the element gives the number of valence electrons. The Lewis symbol includes only the valence electrons for the element.

Using the table of electronegativities provided arrange the following bonds in order of increasing ionic character. (Place the least polar bond at the top of the list.)

Pd-H C-H N-O F-Cl

The formation of an ionic bond involves a number of different processes. If we consider the separate electron transfer processes involved in the formation of sodium chloride, which individual steps would require an input of energy? The overall process is represented by the equation shown below. Select all that apply. 2Na (s) + Cl2 (g) → 2NaCl (s) Attraction of Na+ and Cl- to form NaCl The addition of an electron to each Cl atom Removal of an electron from Na Dissociation of Cl2 to form 2Cl Conversion of Na (s) → Na (g)

Removal of an electron from Na Dissociation of Cl2 to form 2Cl Conversion of Na (s) → Na (g)

Match each type of chemical bond to the correct description. Covalent Bond Ionic Bond Metallic Bond

Sharing of electrons between two atoms due to the attraction between the nucleus of each atom and the electrons of the other The attraction between two oppositely charged particles formed by the transfer of electrons between two atoms Sharing of all valence electrons as an "electron sea" by all the atoms of the substance

Which statement below correctly describes an ionic compound? The compound is a hard solid that can be shaped with a hammer, is not soluble in water, and conducts electricity in the solid and liquid states. The compound is a soft solid that dissolves readily in water. Neither the solid nor the solution conducts electricity. The compound is a solid at room temperature, does not conduct electricity, and dissolves in water to give a solution that conducts electricity.

The compound is a solid at room temperature, does not conduct electricity, and dissolves in water to give a solution that conducts electricity.

Which of the following factors affect the magnitude of the lattice energy for an ionic compound? Select all that apply. The size of the ions The total number of positive and negative ions present The charges of the ions The number of valence electrons in the ions The arrangement of the ions in the crystal

The size of the ions The charges of the ions The arrangement of the ions in the crystal

Select the type of chemical bond that most commonly forms between each combination of elements as indicated. Metallic bond Covalent bond Ionic bond

Two or more metal atoms Nonmetal to nonmetal Metal to nonmetal

The formation of an ionic compound involves the transfer of electrons. The removal of one or more electrons from a metal is a process that _____ energy, whereas the addition of one or more electrons to a nonmetal _____ energy.

absorbs; releases

In general, electronegativity _____ as atomic size increases because a shared electron pair is closer to the nucleus of a smaller atom, which therefore attracts these electrons _____ strongly. Electronegativity tends to _____ from left to right across a period of the periodic table and tends to _____ down a group.

decreases; more; increase; decrease

The relative ability of a bonded atom to attract shared electron pairs is called its _____. This ability _____ as the size of the atom decreases because for a smaller atom the shared electrons will be closer to the nucleus.

electronegativity; increases

From left to right, Period 3 chlorides exhibit a gradation in bond type from ______ to ______ to ______.

ionic; polar covalent; nonpolar covalent

The character of a bond is related to the difference in the electronegativities of the bonded atoms. Match each ΔEN range with the appropriate bond type. Instructions ΔEN = 0 ΔEN < 0.4 ΔEN between 0.4 - 1.7 ΔEN > 1.7

nonpolar covalent mostly covalent polar covalent ionic

A covalent bond in which the electrons are shared unequally is called a(n) -- covalent bond. The atoms of the bond have partial negative and positive -- due to unequal electron distribution. Listen to the complete question

polar, charges

In general the formation of a chemical bond lowers the _____ energy of a chemical system, leading to a _____ stable arrangement.

potential, more

An ionic solid does not conduct electricity in the solid state because the ions are held together by -- attractive forces and cannot move from their positions in the crystal structure. If the solid melts or dissolves in water, the ions are free to move and carry a(n) -- current.

strong electric

To draw the Lewis electron-dot symbol for a main-group element, first determine the number of -- electrons by noting the -- number of the element. Place one -- for each electron on each of the four sides of the element symbol, pairing them up once each site has an electron.

valence A group dot