chemistry test ch.7
How does calcium obey the octet rule when reacting to form compounds? It gains electrons. It gives up electrons. It does not change its number of electrons. Calcium does not obey the octet rule.
It gives up electrons.
What is the formula for sodium sulfate? NaSO ₄ Na(SO₄)₂ Na₂SO ₄ Na₂(SO₄)₂
Na₂SO ₄
An ionic bond is a bond between ____. a cation and an anion the ions of two different metals valence electrons and cations the ions of two different nonmetals
a cation and an anion
a depiction of valence electrons around the symbol of an element covelant bond octet rule ionic bond electron dot structure valence electron diatomic molecules metallic bond
electron dot structure
Chemical bonds between atoms involve the rearranging of __________ to maximize stability.
electrons
Which of the following particles are free to drift in metals? protons neutrons electrons cations
electrons
The attraction between opposite electrical charges is called a(n) __________ force.
electrostatic
A formula unit is the same thing as a molecule. t/f
f
All covalent molecules exhibit polarity. t/f
f
Atoms with fewer than four valence electrons tend to gain electrons when bonding. t/f
f
Because of its high electronegativity, a molecule of fluorine is polar. t/f
f
Conventional plastics, which are covalently bonded, tend to break down easily and degrade quickly in landfills. t/f
f
Diatomic elements such as I 2 exhibit ionic bonding. t/f
f
Except for the transition and inner transition metals, the octet rule applies to all other elements. t/f
f
Ionic compounds have considerably lower boiling points than polar covalent compounds have. t/f
f
Linus Pauling is famous for developing two-dimensional diagrams to show the bonds between atoms. t/f
f
Solid ionic substances conduct electricity easily. t/f
f
There are four unshared pairs of electrons in a water molecule. t/f
f
When atoms bond, they will seek a higher, more stable energy state. t/f
f
The ratio of cations to anions in an ionic compound is expressed in a chemical formula known as a(n) __________.
formula unit
The number of valence electrons for nonmetals (except hydrogen) can be predicted by the formula valence e- = _________ ________ -10.
group number
Which of the following compounds has the formula KNO₃? potassium nitrate potassium nitrite potassium nitride potassium nitrogen oxide
potassium nitrate
What is the net charge of the ionic compound calcium fluoride? 2- 0 1- 1
0
What is the charge on the cation in the ionic compound sodium sulfide? 0 2 1 3
1⁺
What is the maximum charge an ion is likely to have? 2 4 3 5
3
What makes a bond polar?
A covalent bond is polar when one of the two atoms has a higher electronegativity than the other. This causes the bonding electrons to spend more time at one end of the bond, resulting in a positive and negative pole for the bond.
Predict the formula unit of the ionic compound that will form from Al and Cl according to the number of valence electrons.
AlCl₃
What is the formula unit of aluminum oxide? AlO ₃ AlO Al₃O Al₂O₃
Al₂O₃
Why are the diatomic elements not found in nature as single atoms?
Diatomic elements have very high electron affinities. Being single atoms, they quickly form bonds with other elements around them. They are relatively stable only when in the diatomic state.
Which of the following are covalent compounds? Select all that apply. CsI CCl₄ PO₄³⁻ Na₂O I₂ Zn
CCl₄ PO₄³⁻ I₂
Which of the following are ionic compounds? Select all that apply. CsI CCl₄ PO₄³⁻ Na₂O I₂ Fe₃Al
CsI PO₄³⁻ Na₂O
How does oxygen obey the octet rule when reacting to form compounds? It gains electrons. It gives up electrons. It does not change its number of electrons. Oxygen does not obey the octet rule.
It gains electrons.
Compare the three types of bonding on the basis of electron location.
In covalent bonding, one or more electrons are shared between atoms with similar electronegativities. They are often shared unequally. Ionic bonds involve the transfer of one or more electrons so that they spend most of their time around the atom with the stronger attraction. In metallic bonding, the valence electrons are delocalized and move freely in an electron sea between the metallic cations.
Contrast the electrons found in metallic bonds with those in covalent bonds.
In metallic bonds, the electrons are loosely held and are mobile, moving freely among many atoms. No single atom has exclusive use of any electron. In covalent bonds, neither atom completely releases its electrons, but they are shared in such a way that each atom achieves a full valence shell.
Which of the following occurs in an ionic bond? Oppositely charged ions attract. Two atoms share two electrons. Two atoms share more than two electrons. Like-charged ions attract.
Oppositely charged ions attract.
A covalently bonded anion is a _________________________ ion.
Polyatomic
Predict the formula unit of the ionic compound that will form from Sr and F according to the number of valence electrons.
SrF₂
In general, how do the stability and energy of bonded atoms compare with that of unbonded atoms?
Stability is greater and energy is lower for bonded atoms.
How do intermolecular forces affect the melting point of a compound?
Stronger intermolecular forces within a compound increase the melting point.
What characteristic of metals makes them good electrical conductors? They have mobile valence electrons. They have mobile protons. They have mobile cations. Their crystal structures can be rearranged easily.
They have mobile valence electrons.
Which of the following is true about an ionic compound? It is a salt. It is composed of anions and cations. It is held together by ionic bonds. all of the above
all of the above
A mixture of atoms of a metal with another element where the mixture has metallic properties is called a(n) __________.
alloy
The electrons shared in a covalent bond are called the __________ pair.
bonding
Predict the predominant type of bonding associated with each of the following. covalent metallic ionic CCl₄
covalent
Predict the predominant type of bonding associated with each of the following. covalent metallic ionic I₂
covalent
Predict the predominant type of bonding associated with each of the following. covalent metallic ionic PO₄³⁻
covalent
Predict the predominant type of bonding associated with each of the following. covalent metallic ionic one or more pairs of shared electrons
covalent
The compound CCl₄ is an example of __________ bonding.
covalent
have similar electronegativities and are usually non-metals covelant bond octet rule ionic bond electron dot structure valence electron diatomic molecules metallic bond
covelant bond
to exist in a pure form they must bond to themselves covelant bond octet rule ionic bond electron dot structure valence electron diatomic molecules metallic bond
diatomic molecules
Compounds formed by the attraction between oppositely charged ions are held by __________ bonds.
ionic
Predict the predominant type of bonding associated with each of the following. covalent metallic ionic CsI
ionic
Predict the predominant type of bonding associated with each of the following. covalent metallic ionic Na₂O
ionic
Predict the predominant type of bonding associated with each of the following. covalent metallic ionic attraction between oppositely charged ions
ionic
The compound CsI is an example of __________ bonding.
ionic
the force of attraction binding oppositely charged ions together covelant bond octet rule ionic bond electron dot structure valence electron diatomic molecules metallic bond
ionic bond
What is the name of the ionic compound formed from lithium and bromine? lithium bromine lithium bromium lithium bromide lithium bromate
lithium bromide
Predict the predominant type of bonding associated with each of the following. covalent metallic ionic Fe₃Al
metallic
Predict the predominant type of bonding associated with each of the following. covalent metallic ionic Zn
metallic
Predict the predominant type of bonding associated with each of the following. covalent metallic ionic electron-sea theory
metallic
The compound Fe₃Al is an example of __________ bonding.
metallic
the attraction of valence electrons for metal ions covelant bond octet rule ionic bond electron dot structure valence electron diatomic molecules metallic bond
metallic bond
Atoms seek to gain, lose, or share electrons to achieve the electron configuration of which group of elements?
noble gases
Atoms attain stability by having a full valence shell of electrons according to the __________.
octet rule
Atoms react so as to acquire the stable electron structure of a noble gas. covelant bond octet rule ionic bond electron dot structure valence electron diatomic molecules metallic bond
octet rule
Which of the following are associated with ionic compounds? Select all that apply. opposite charges attract hard, brittle solids nonmetals with nonmetals form molecules formula units
opposite charges attract hard, brittle solids formula units
Although they are made of two or more atoms, __________ ions often act as single charged particles in chemical reactions and solutions.
polyatomic
When nonmetals chemically combine with each other, they __________ electrons, forming __________ bonds.
share, covalent
Which of the following are associated with metallic bonding? Select all that apply. hard, brittle solids shiny, malleable electron carriers atoms with high electronegativities electron-sea theory atoms with weak electron affinities
shiny, malleable electron carriers electron-sea theory atoms with weak electron affinities
Which of the following are network covalent substances? Select all that apply. water silicates diamond oxygen carbon dioxide quartz
silicates diamond carbon dioxide
Completely nonpolar bonds exist. t/f
t
Covalently bonded compounds contain one or more pairs of shared electrons. t/f
t
Ionic compounds are more likely to fracture than are covalent compounds. t/f
t
Ionic compounds are not made of distinct molecules as are covalent compounds. t/f
t
It is impossible to have a completely ionic bond. t/f
t
It is improper to refer to sodium chloride as a molecule. t/f
t
Polar covalent bonds result when the atoms sharing the electrons have differing electronegativities. t/f
t
Some covalent substances occur as relatively hard, brittle crystals with high melting points, glassy lusters, and unusual electrical properties. t/f
t
The compound Na 2 O exhibits ionic bonding. t/f
t
The greater the difference in electronegativity between two elements, the greater the polarity of the resulting bond. t/f
t
The total number of electrons shown in a Lewis structure must equal the total number of valence electrons provided by the atoms in the molecule. t/f
t
When drawing Lewis structures, some atoms may need to share more than one electron pair with another atom to satisfy the octet rule. t/f
t
When sodium and chlorine combine to form NaCl, a great amount of energy is released. t/f
t
What is the basis of a metallic bond? the attraction of metal ions to mobile electrons the attraction between neutral metal atoms the neutralization of protons by electrons the attraction of oppositely charged ions
the attraction of metal ions to mobile electrons
an electron in the highest occupied energy level of an atom covelant bond octet rule ionic bond electron dot structure valence electron diatomic molecules metallic bond
valence electron
