Ch. 9 LearnSmart

Which of the following statements correctly describe ionic bonding?

*An ionic bond is the electrostatic between two oppositely charged ions. *Ionic bonding involves the transfer of electrons from metal to the nonmetal

Which of the following options correctly describe electronegativity?

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

Which of the following options correctly describe the general trends in electronegativity?

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

Electronegativity bonds *ΔEN=0 *ΔEN<0.4 *ΔEN between 0.4-1.7 *ΔEN>1.7

*Nonpolar covalent *Mostly covalent *Polar covalent *Ionic

As the ΔEN for a particular bond increases, the character of the bond changes and this is often reflected in the behavior of a substance. The ΔEN for the K-Br bond is 2.0 and ΔEN for the Au-Br bond is ΔEN. Match each statement about the K-Br and Au-Br bonds correctly to the descriptions.

*The K-Br bond is more --> ionic in character *The AU-Br bond is more --> covalent in character *KBr is expected to have --> a relatively high melting point *AuBr2 is expected to have --> a relatively low melting point

Which statement correctly describes the general characteristics of a covalent bond?

*The covalent bond involves the attraction between the nucleus of each atom and the electrons of the other. *A covalent bond involves the sharing of electrons between two atoms.

The formation of an ionic bond involves a number of different processes. In the formation of Sodium Chloride, represented by the equation given below, which steps require an input of energy? 2Na (s) + CL2 (g) --> 2NaCl (s)

*The dissociation of Cl2 to form 2Cl *Conversion of Na (s) --> Na (g) *Removal of an electron from Na

Which of the following statements correctly describe trends in lattice energy?

*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.

Which statement correctly describes the general characteristics of a metallic bond?

*The metal is held together by the attraction between the metal-ion cores and the sea of valence electrons *All the valence electrons of the bonded metal atoms are shared in an electron sea. *The electron sea is able to move freely through the metallic structure.

The relationship between bond order, bond length, and bind energy.

*The shorter the bond, the greater the bond strength *For a given pair of atoms, a higher bond order means a shorter bond

How to calculate the oxidation number (O.N.) of a covalently bonded atom using electromagnetically

1. The more electronegative atom in a bond is assigned all the shared electrons; the less electronegative atom is assigned none. 2. Each atom in a bond is assigned all of its unshared electrons. 3. The oxidation number is given by O.N. = # of valence electrons - (# of shared electrons + # of unshared electrons)

A pair of electrons shared between two atoms in a covalent bond is called a shared or ____ electron pair, whereas an outer-level electron pair that isn't involved in bonding is called an unshared or ____ pair.

Bonding, lone

Which of the following descriptions applies to an ionic compound.

Compound A is a solid at room temperature and does not conduct electricity. Compound A dissolves in water to give a solution that conducts electricity readily.

Most covalently bonded substances consist of individual separate molecules. Each individual molecule is held together by means of strong ___ bonds between the atoms. In addition, there are weak forces of attraction between the individual molecules, called ____ forces.

Covalent, intermolecular

The bond formed between two nonmetal atoms is called a ____ bond. This type of bond arises from the net attraction between the ____ of each atom and the electrons of the other, and results in electrons being ____ between the two atoms.

Covalent, nucleus, shared

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

Electronegativity, increases

The partial ionic character of a bond is related to the difference in the electronegativities of the bonded elements. The greater the EN, the ____ the percent ionic character of the bond. Although there are many bonds that have 0% ionic character, no bond has 100% ionic character, which indicates that electron ____ occurs to some extent in every bond

Greater, sharing

Arrange the following ionic compounds in order of decreasing lattice energy, based on general periodic trends: KBr, Na2 O, MgO ...

MgO Na2 O KBr

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+

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

Potential, more

Metals have low ionization energies and readily share their ____ or outer electrons with each other to form an electron ____. These electrons are ____ or shared among all the atoms that are bonded together and can therefore move freely throughout the metal structure.

Valence, sea, delocalized

The amount of energy required to separate 1 mole of ions in a crystalline solid into separate gaseous ions is called ____ energy. This energy provides a measure of the strength of a(n) ____ bond, since the stronger the bond the ____ the amount of energy required to break it.

lattice, ionic, greater

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