CHEMISTRY CHAPTER 8
A magnesium atom is most likely to have what charge as an ion?
+2
A sigma bond occurs when _____.
two orbitals directly overlap but there is only one bonding interaction.
Which are the outermost electrons of an atom?
valence electrons
What do some molecules have resonance?
Because electrons are mobile and will move to different positions within a molecule if they can.
Why are metals malleable?
Because the atoms can move freely without harming the crystal structure.
Why are metals shiny?
Because they reflect light photons
What happens when both of the orbitals in a molecule are in a phase, either both positive or both negative, and the electrons in the bonds are their lowest energy level?
Bonding takes place.
When is it possible to form multiple bonds with the same partner atom?
If the atom has enough valence electrons.
Which is the best definition of a covalent compound?
a compound formed from the sharing of electrons between two or more nonmetal atoms.
What is usually the first step when drawing a Lewis dot structure?
Summing the number of valence electrons.
A polar molecule, such as the one involved in a hydrogen bond, is sometimes called _____.
a dipole
An ionic compound is formed by what?
a metal cation and a non-metal anion
What is the octet rule?
a rule that says atoms like to have full valence shells of eight electrons
In chemistry, the Greek letter delta:
is a symbol which designates difference or change
How many valence electrons are in a carbon dioxide (CO2) molecule?
16
If a central atom of a molecule only has two electron domains, what is the bond angle associated with the molecule?
180°
How many dots would you put around carbon, a group IVA element?
4
If a silicon atom has four valence electrons, what is the maximum number of bonds it can form?
4
How many dots should be around an elemental symbol in a Lewis dot diagram if it has a full octet?
8
How many total dots should the diagram for silicon tetrahydride, SiH4 include?
8
What is a nonbonding electron domain?
A lone pair of electrons
What is a polar molecule?
A molecule with a slightly positive side and a slightly negative side.
How does an atom try to fill its valence shell?
All answers are correct; by adding electrons, by sharing electrons, and by giving away electrons.
What is an anion?
An atom that has gained a valence electron and is negatively charged.
An ionic bond occurs when a _____ and an _____ come together and form a bond.
Cation: Anion
Which of the following would be good at conducting energy?
Copper
If a polyatomic ionic compound has gained two hydrogen ions, then how does its name begin?
Dihydrogen
What type of intermolecular force exists between polar molecules?
Dipole-dipole
What charge do group IVA atoms have when they become ions?
Either +4 or -4, but they don't usually become ions.
Why must we consider a molecule's shape when determining its polarity?
The shape reveals more about distribution of charge than the Lewis dot structure
In larger atoms, why can outer electrons move more freely?
Electrons are filling higher energy shells, which means that they're farther from the nucleus, and are thus less tightly held.
How many bonding domains are needed for a molecule to have a tetrahedral shape?
Four
What does bond order refer to?
How many bonds there are between two atoms.
Which of the following statements is true regarding hydrogen bonds?
Hydrogen bonds are weaker than covalent and ionic bonds.
Which of the following statements is true? I. In an ionic bond, electrons move toward the atom that is more electronegative. II. A cation is a negative charged atom. III. A positively charged atom is called an anion. IV. Under biological conditions, ionic bonds are stronger than covalent bonds.
I
What differentiates a non polar covalent bond from a polar covalent bond? I. Unequal sharing of electrons II. Ions III: Atoms of partial charge
I and III
If a carbon atoms has four valence electrons, which of the following statements are true? I. Carbon can form a triple covalent bond with another carbon atom. II. A carbon atom cannot form two double bonds simultaneously. III. A carbon atom can form four single covalent bonds simultaneously.
I and III.
Hydrogen bonds occur between hydrogen in one polar molecule and _____ in another polar molecule. I. Oxygen II. Fluorine III. Nitrogen
I, II, and III
Which of the following statements are true? I. Noble gases complete their valence level by sharing electrons. II. Covalent bonds are weak and easily broken. III. Covalent bonds allow us to make predications on how the molecule will look.
III
How are metallic bonds different from ionic and covalent bonds?
In metallic bonds, electrons are free floating. They are not transferred or shared like in ionic or covalent bonds.
If oxygen with an electronegativity of 3.4 were to share electrons with lithium, the electronegativity of 1.0, what kind of bond would form?
Ionic
What type of bond forms when atoms have highly different electronegative?
Ionic Bond
How are ions formed?
Ions are formed when neutral atoms gain or lose electrons to become positively or negatively charged.
What is the correct name for Fe(OH)3?
Iron (III) hydroxide
Which of the following statements BEST explains the molecular orbital theory?
It describes how the orbital shapes combine when atoms combine into molecules.
What happens when a neutral molecule becomes temporarily dipole?
It induces a temporary dipole on a nearby molecule.
How do you know how many hybrid orbitals are formed?
It is the same as the number of atomic orbitals that participate in the process.
What is the correct name for MgCl2?
Magnesium (II) chloride
Which of the following will most likely have the highest lattice energy?
MgO +2, -2 charge
Which of the following is an example of an ionic compound?
NaCl
Identify the atom that is likely to have the highest electronegativity.
Non-metal oxygen, atomic number 8
If carbon, electronegativity of 2.6 were to share electrons with sulfur, electronegativity 2.6, what kind of bond would it form?
Non-polar covalent
How many bonds can hydrogen form?
One
Electron clouds:
Predict where electrons will be found around an atom or molecule
Which of the following atoms is most likely to participate in an ionic bond with chlorine, an atom with 7 valence electrons?
Sodium (1 valence electron)
What is an intermolecular force?
The attractions between molecules
What is wrong with the Lewis dot structure for IO-
The bond between I and O should be represented with a single line.
What does the charge on a polyatomic ion mean?
The charge on a polyatomic ion is equivalent to the number of electrons the parent molecule most lose or gain to achieve the octet rule.
What is bond energy?
The energy needed to break bonds.
Which of the following is true of intermolecular forces?
The forces that exist between molecules
What is hybridization?
The mixing of two or more atomic orbitals to form new orbitals that describe the covalent bonding in molecules.
What is the electron sea model?
The model of metallic bonding where electrons float free in a sea of electrons around metal atoms.
Identify the requirement for a dipole-dipole force to exist.
The molecules need to be very close to each other.
Why does hybridization work?
The net energy of the molecule is less than that of the atoms in isolation.
When naming a binary compound, what determines the prefix for an element in the compound?
The number of atoms of that element in the compound.
What is the first think you need to know to use the hybridization theory?
The number of valence electrons in the participating atoms.
What happens in constructive interference?
The orbitals add.
Which of the following best describes the octet rule?
The outermost energy shell of an atom likes to be full with eight electrons.
What is a binary compound?
a compound composed of only two elements
What is a London dispersion force?
The weak intermolecular force that results from the motion of electrons that creates temporary dipoles in molecules.
How do you determine which way the dipole arrow points?
Towards the more electronegative atom.
What is the shape of a Boron Trifluoride molecule, BF₃?
Trigonal planar
When drawing Lewis dot structures, what should you do if you run out of electrons before all atoms are satisfied?
Try double or triple bonds.
In a Lewis dot structure, what do the dots represent?
Valence electrons.
Why is water a bent molecule and not linear?
Water has four electron domains (two bonding regions and two pairs of unbound electrons) repelling each other, causing the molecule to be bent.
What is the best definition for resonance?
When a molecule or polyatomic ion has more than one correct Lewis dot structure.
Which of the following best describes the term dipole moment?
When electrons are unevenly distributed within a molecule.
How is a covalent bond formed?
When electrons between atoms are shared.
What causes a dipole?
When the electrons are concentrated more at one end of a molecule, that end is slightly negative, and the other end, where the electrons aren't as concentrated, is slightly positive.
When is a polar covalent bond formed?
When the shared pair of electrons are more attracted to one atom than the other.
How are resonance structures for a molecule or polyatomic ion represented?
With a double-heated arrow in between each structure.
Hydrogen bonds exist between X and Y. Which combination could be X and Y?
X is water, H2O Y is ammonia, NH3
Which of the following is MOST likely to result in a hydrogen bond?
a water molecule with another water molecule.
Intermolecular forced do NOT have effect on _____.
acidity
What is a valence electron?
an electron at the highest occupied energy level of an atom
A hydrogen bond is _____.
an intermolecular force
If an ionic compound contains a transition metal, Roman numerals are used to determine the _____.
charge on the ion.
Which of the following is a property of an ionic compound?
crystal lattice structure
What is the correct name for N2O5.
dinitrogen pentoxide
An anion has a(n) _____ charge.
negative
London dispersion force is the only intermolecular force that works on _____.
noble gases and non polar molecules
Two atoms with the same electronegativity would form what kind of bond?
nonpolar covalent
A cation has a _____ charge.
positive
Which of the following is NOT a property of covalent compounds?
superior malleability
What do you look at in the periodic table to determine the number of valence electrons possessed by an element?
the element's group number
What does a Lewis dot diagram allow you to show?
the valence electrons in an element.
How do you represent a triple bond in a structural formula?
three horizontal lines/six dots
How is an ionic bond formed?
through the transfer of electrons
