Chemical Bonding Test

What is the charge of a particle having 12 protons and 10 electrons?

+2

What is the charge of a particle having 9 protons and 10 electrons?

-1

water bond angle

104.5

trigonal pyramidal bond angle

107

tetrahedral bond angle

109.5

In a hexagonal close-packed crystal, every atom (except those on the surface) has ____ neighbors.

12

bond angle of trigonal planar

120

bent bond angle

120 or 104.5 (H2O)

bond angle of linear

180

What is the total number of covalent bonds in a covalently bonded molecule containing one oxygen and two hydrogen atoms?

2

How many valid electron dot formulas—having the same number of electron pairs for a molecule or ion—can be written when a resonance structure occurs?

2 or more

How many covalent bonds are in a covalently bonded molecule containing 1 phosphorus atom and 3 chlorine atoms?

3

How many extra electrons are in the Lewis structure of the phosphate ion, PO43-?

3

Why does helium need only two valence electrons?

A helium atom needs only two valence electrons because they fill the first energy level, which is also its outermost energy level.

the electron dot structure for water

H : O : . . H

Which of the following shows both the correct formula and correct name of an acid?

HPO, phosphoric acid

the chemical formula for an ionic compound represents the

MOLECULES are not the representative particle of ionic compounds. FORMULA UNITS are the representative particle of ionic compounds. Formula units represent the smallest whole number ratio of cations to anions. The correct answer is: simplest ratio of the combined ions that balances total charges.

shapes adjust so valence-electron pairs are as far apart as possible

VSEPR theory

electron dot structure

a depiction of valence electrons around the symbol of an element

a polar molecule contains

a region of a positive charge and a region of a negative charge

covalent bonding

also called a molecular bond, is a chemical bond that involves the sharing of electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs, and the stable balance of attractive and repulsive forces between atoms, when they share electrons, is known as covalent bonding.

Ionic compounds conduct electricity better in the molten state than in the solid state.

always true

Which of the following orbital types has the highest energy?

anti-bonding orbital

hydrogen bonds

attractive forces in which a hydrogen covalently bonded to a very electronegative atom is also weakly bonded to an unshared electron pair of another electronegative atom

According to molecular orbital theory, why does a covalent bond form?

because electrons have a lower energy in a bonding orbital than they do in their atomic orbitals and, therefore, the bonded structure is more stable.

pi bonds

bonding electrons are most likely to be found in sausage shaped regions above and below the bond axis of the bonded atoms. Atomic orbitals in pi overlap less than in sigma bonding. Pi bonds are weaker than sigma bonds.

molecular orbital that can be occupied by two electrons of a covalent bond

bonding orbital

The strength of London dispersion forces between molecules depends on

both the number of electrons in the molecule and the mass of the molecule.

Alloys are commonly used in manufacturing. Which of the following is a reason to use an alloy instead of a pure metal?

bronze is tougher than pure copper

atoms, or groups of atoms with a positive charge

cations

What does a piece of metal consist of?

closely packed cations surrounded by mobile valence electrons.

a covalent bond between two atoms in which the shared electron pair comes from only one of the electrons

coordinate covalent bond

In its simplest form, the alloy brass consists of zinc and

copper

attraction between polar molecules

dipole dipole

interaction caused by the motion of electrons

dispersion force

a covalent bond formed by the equal sharing of bonding electrons; each atom donates one pair of electrons to the bond

double covalent bond

the ability of metal to be drawn into wires is

ductility

In metallic bonds, the mobile electrons surrounding the positive ions are called an

electron sea

polar covalent bond

electrons shared by the atoms spend a greater amount of time, on the average, closer to the Oxygen nucleus than the Hydrogen nucleus.

Which of these is not a characteristic of most ionic compounds?

has a low melting point

is the melting point of potassium chloride low or high

high

You are given the melting points of three unknown substances and asked to predict which is an ionic compound. You would select the compound with the ____________________ melting point.

highest

The mixing of two or more atomic orbitals of similar energies on the same atom to produce new orbitals of equal energies is called

hybridization

a type of bond that is very important in determining the properties of water and of important biological molecules such as proteins and DNA

hydrogen bond

force that occurs when a hydrogen atom that i covalently bonded to a very electronegative atoms is also weakly bonded to an unshared pair of electrons n the same or a nearby molecule

hydrogen bond

The intermolecular attraction between a hydrogen atom bonded to a strongly electronegative atom and the unshared pair of electrons on another strongly electronegative atom is called

hydrogen bonding

what do you call a bond that forms when electrons are transferred from one atom to another?

ionic bond

Differentiate between an ionic compound and a molecular compound.

ionic compounds are combined in crystal lattices, and once dissolved, they separate one by one. They steal electrons from each other to create a net charge of zero and include a metal and a nonmetal. Molecular compounds combine in chunks of molecules and separate by molecules. They are combined of nonmetals.

what is true about an ionic compound?

it is a salt, it's composed of anions and cations, it's held together by ionic bonds

The ability of metal to be hammered into sheets is

malleability

The bond formed by the attraction between positively charged metal ions and the electrons around them is a

metallic bond

substance in which all of the atoms are covalently bonded to each other

network solid

Which of the following elements can form diatomic molecules held together by triple covalent bonds?

nitrogen

a covalent bond formed by the equal sharing of bonding electrons by two atoms

nonpolar

dipole interactions

occur when polar molecules are attracted to one another and are weaker than ionic bonds

How many electrons can occupy a single molecular orbital?

one

KBr is the formula for an ionic compound. The fact that neither symbol is followed by a subscript means that there is a(an) _________________________ ratio of ions in the compound.

one to one

Under what conditions can potassium bromide conduct electricity?

only when melted or dissolved in water

An overlap of two p orbitals on parallel axes

pi bond

Which of the following bond types is normally the weakest?

pi bond formed by the overlap of two p orbitals

a covalent bond between two atoms of different electronegativities in which the bonding electrons are not shared equally

polar bond

symmetrical bond along the axis between the two nuclei

sigma bond

a covalent bond in which only one pair of electrons is shared by two bonded atoms

single covalent bond

Network Solids

solids in which all of the atoms are covalently bonded to each other-high melting point

VSEPR theory

states that repulsions between electron pairs causes molecular shapes to adjust so that valence-electron pairs stay as far apart as possible

chemical formula that shows the arrangement of atoms in molecules and polyatomic ions

structural formula

what phrase best describes a metallic bond?

the attraction between a metal cation and a shared pool of electrons

A molecule of hydrogen chloride is polar because

the chlorine attracts the shared electrons more strongly than does the hydrogen atom.

What determines molecular properties?

the kind and number of atoms joined together

why can metals bend without breaking?

they contain constantly or delocalized electrons

The elements most likely to form more than one type of ion are the

transition metals

a covalent bond in which three pairs of electrons are shared by two bonded atoms

triple covalent bond

van der Waal forces

two weakest attractions between molecules-consists of dipole interactions and dispersion forces

most atoms bond using what?

valence electrons

Dispersion forces

weakest of all molecular interactions and are cause by the motion of electrons. They occur even between non-polar molecules

sigma bond

when two atomic orbitals combine to form a molecular orbital that is symmetrical around the axis, connecting two atomic nuclei

non polar covalent bond

where two atoms share a pair of electrons with each other. Polar covalent bonding is a type of chemical bond where a pair of electrons is unequally shared between two atoms.

how many valence electrons are transferred from from the nitrogen atom to potassium in the formation of the compound potassium nitride?

zero

what is the net charge of the ionic compound calcium fluoride?

zero