Use this free practice quiz with 20 questions to review 07 Ionic and Covalent Bonding, test your knowledge, and prepare for your next test or exam.
A student compares two properties: one describes how strongly an atom attracts shared electrons in a bond, and the other concerns the energy change when an isolated gaseous atom gains an electron. Which pairing correctly names these properties?
Electronegativity is the energy change when an isolated gaseous atom gains an electron; electron affinity measures attraction for shared electrons in a bond.
Electronegativity describes attraction for shared electrons in a bond; electron affinity concerns the energy change when an isolated gaseous atom gains an electron.
Both terms describe the attraction between oppositely charged ions in a solid lattice.
Both terms measure the energy released when a covalent bond forms.
Using the general periodic trend in electronegativity, which ordering is expected for fluorine, oxygen, and chlorine, from highest to lowest?
Cl > O > F
O > Cl > F
F > O > Cl
Cl > F > O
A student sees the formula NaCl and sketches a single Na–Cl unit as though the solid consisted of separate molecules. Which interpretation best corrects the student's model?
It represents one discrete molecule made from three atoms.
It represents three separate molecules, each containing one ion.
It represents a crystalline lattice whose simplest neutral ion ratio is one sodium ion to one chloride ion.
It represents a covalent pair in which sodium and chlorine share electrons equally.
Aluminum oxide contains Al³⁺ and O²⁻ ions. Which ion ratio makes the solid electrically neutral and explains the subscripts in Al₂O₃?
One Al³⁺ and one O²⁻, because each contributes one ion to the formula.
Two Al³⁺ ions and three O²⁻ ions, because their total charges are +6 and −6.
Three Al³⁺ ions and two O²⁻ ions, because reversing the subscripts keeps the formula neutral.
Two Al³⁺ ions and two O²⁻ ions, because equal numbers of ions always make a neutral solid.
A student claims that KNO₃ must have only one kind of bonding because it is written as a single formula. Which description best accounts for the bonding in this compound?
The K–N and N–O bonds are all ionic because the formula contains a metal.
The K–O and N–O bonds are all covalent because nitrate contains nonmetals.
Only the N–O bonds are ionic; potassium is held in place by covalent sharing.
Attraction between K⁺ and NO₃⁻ is ionic, while the N–O bonds within NO₃⁻ are covalent.
An ionic compound does not conduct electricity as a solid but does when molten. Which explanation best accounts for this change without assuming that the ions become neutral?
The solid's ions are fixed in place, but the molten material contains mobile ions that can carry charge.
Melting changes the ions into neutral atoms, which then conduct electricity.
The molten material conducts because melting breaks every ionic attraction and releases electrons.
The solid conducts, but the molten material does not, because ions can move only in a crystal.
A molecular covalent substance melts at a relatively low temperature. Which conclusion avoids confusing the attractions between molecules with the bonds inside each molecule?
Its covalent bonds must be weaker than the attractions between its molecules.
The molecules become ions as soon as the substance melts.
Melting usually separates molecules from one another rather than breaking their internal covalent bonds.
The substance cannot contain strong covalent bonds if its melting point is low.
A reaction description says that one covalent bond is broken and another is formed. Which statement correctly assigns the energy change to each event?
Both breaking and forming a bond require energy.
Breaking a bond requires energy; forming a bond releases energy.
Breaking a bond releases energy; forming a bond also releases energy.
Breaking a bond releases energy; forming a bond requires energy.
For two bonds between the same pair of atoms, what general comparison is expected when one is a multiple bond and the other is a single bond?
A multiple bond is generally longer and weaker than a single bond, regardless of the atoms involved.
A multiple bond is generally shorter but weaker than a single bond for the same pair of atoms.
Single and multiple bonds for the same pair of atoms have the same typical length and strength.
A multiple bond is generally shorter and stronger than a single bond for the same pair of atoms, though exact values depend on the atoms and their environment.
A potential-energy curve for two bonded atoms has a minimum. What does the internuclear distance at that minimum represent?
The internuclear distance at which the bonded atoms have their lowest potential energy.
The distance at which two separated atoms have their greatest potential energy.
The amount of energy required to break a covalent bond.
The distance between neighboring molecules in a liquid.
A reference chart labels bonds as ionic above a specific electronegativity-difference cutoff. Which conclusion is most scientifically appropriate when a bond lies near that cutoff?
A particular electronegativity-difference cutoff universally proves that a bond is completely ionic.
Every bond with a nonzero electronegativity difference must be classified as ionic.
Electronegativity difference helps estimate polarity and ionic character, but category boundaries are approximate because bonding lies on a continuum.
Electronegativity difference cannot give any information about how equally a bond shares electrons.
A solid contains Al³⁺ and O²⁻ ions. Which formula gives the simplest whole-number ratio that makes the ionic solid electrically neutral?
AlO
Al₂O₃
Al₃O₂
Al₂O
An ionic compound does not conduct electricity as a solid but does conduct when molten. Which explanation best accounts for both observations?
The solid conducts because its ions move through the lattice, while melting makes them stationary.
The solid and melt conduct equally because ionic compounds contain electrons that move freely in both states.
The solid does not conduct because its ions are fixed in place, but the melt can conduct because its ions are mobile.
The solid does not conduct because it contains neutral molecules, but the melt conducts because those molecules become charged.
In an H–Cl bond, chlorine attracts the shared electrons more strongly than hydrogen. Which description correctly combines the bond type and the direction of its partial charges?
The bond is polar covalent, with chlorine partially negative and hydrogen partially positive.
The bond is polar covalent, with chlorine partially positive and hydrogen partially negative.
The bond is nonpolar covalent because the atoms share electrons rather than transfer them.
The bond is ionic because any unequal sharing means electrons have been fully transferred.
Which statement correctly distinguishes electronegativity from electron affinity?
Electronegativity measures the energy released when an isolated gaseous atom gains an electron; electron affinity measures attraction for shared electrons in a bond.
Both terms describe the attraction between oppositely charged ions in a solid.
Electronegativity measures how readily an atom loses an electron; electron affinity measures how strongly it attracts a neighboring atom's nucleus.
Electronegativity describes attraction for shared electrons in a bond; electron affinity concerns the energy change when an isolated gaseous atom gains an electron.
Two samples contain the same pair of atoms in comparable chemical environments, one joined by a single bond and the other by a double bond. Which comparison is generally expected?
The double bond is generally longer and weaker because it contains more shared electron density.
The double bond is generally shorter and stronger, although exact bond properties depend on the atoms and their chemical environment.
The two bonds must have identical lengths and strengths because they connect the same elements.
The double bond is generally shorter but weaker, because shortening a bond reduces the attraction between the atoms.
A molecular covalent substance melts at a relatively low temperature. Which conclusion best explains why this observation does not show that its internal covalent bonds are weak?
Its covalent bonds are necessarily weak, so they break at a low temperature.
Its molecules become ions as soon as the substance melts.
Melting usually separates molecules from one another without breaking their internal covalent bonds.
Its atoms separate completely because melting destroys the shared electron density in every molecule.
Which description correctly identifies the bonding in potassium nitrate, KNO₃, at both the ion-pair level and within the nitrate ion?
Both the attraction between K⁺ and NO₃⁻ and the N–O bonds are ionic.
The K–NO₃ interaction is covalent, while the N–O bonds are ionic.
The attraction between K⁺ and NO₃⁻ is ionic, while the N–O bonds within NO₃⁻ are covalent.
Every bond in KNO₃ is covalent because its formula contains more than two elements.
Bond P–Q has an electronegativity difference of 0.7, while bond W–X has a difference of 1.8. Which conclusion is best supported without assuming a universal numerical cutoff between bond categories?
Bond P–Q must be ionic and W–X must be covalent because a larger difference always means covalent bonding.
Bond W–X has more unequal sharing and greater ionic character than P–Q, but the values alone do not establish a universal categorical boundary.
Both bonds must be purely covalent because any shared electron density rules out ionic character.
Bond P–Q has greater ionic character because its smaller difference allows the atoms to share electrons less equally.
A neutral metal atom M transfers one electron to a neutral nonmetal atom X. Which statement best describes the resulting ions and the interaction that holds them together?
M becomes an anion and X becomes a cation; their attraction results from sharing electron density.
M becomes a cation and X becomes an anion; their opposite charges attract electrostatically.
Both atoms become cations because M transfers an electron to X.
M and X remain neutral; the ionic bond is the electron moving from one atom to the other.