Chemistry (Chapter 8)

Question 1

What is a covalent bond?

Answer 1

A bond formed by the sharing of electrons between atoms.

Question 2

What is a molecule?

Answer 2

A neutral group of atoms joined together by covalent bonds.

Question 3

What is a diatomic molecule?

Answer 3

A molecule consisting of two atoms.

Question 4

What is a molecular compound?

Answer 4

A compound that is composed of molecules.

Question 5

What is a molecular formula?

Answer 5

A chemical formula of a compound that shows the kinds and number of atoms present in a molecule of a compound.

Question 6

What is a single covalent bond?

Answer 6

A bond formed when two atoms share a pair of electrons.

Question 7

What is a structural formula?

Answer 7

A chemical formula that shows the arrangement of atoms in a molecule or a poly-atomic ion; each ash between a pair of atoms indicates a pair of shared electrons.

Question 8

What is an unshared pair?

Answer 8

A pair of valence electrons that is not shared between atoms.

Question 9

What is a double covalent bond?

Answer 9

A bond in which two atoms share two pairs of electrons.

Question 10

What is a triple covalent bond?

Answer 10

A covalent bond in which three pairs of electrons are shared by two atoms.

Question 11

What is a coordinate covalent bond?

Answer 11

A covalent bond in which one atom contributes both bonding elements.

Question 12

What is a polyatomic ion?

Answer 12

A tightly bound group of atoms that behaves as a unit and has a positive or negative change.

Question 13

What is bond dissociation energy?

Answer 13

The energy that is required to break the bond between two covalently bonded atoms; this value is usually expressed in kJ per mol of substance.

Question 14

What is resonance structure?

Answer 14

One of the two or more equally valid electron dot structures of a molecule or polyatomic ion.

Question 15

What is a molecular orbital?

Answer 15

An orbital that applies to the entire molecule.

Question 16

What is a bonding orbital?

Answer 16

A molecule orbital that can be occupied by two electrons of a covalent bond.

Question 17

What is a sigma bond?

Answer 17

A bond formed when two atomic orbitals combine to form a molecular orbital that is symmetrical around that axis connecting the two atomic nuclei.

Question 18

What is a Pi bond?

Answer 18

A covalent bond in which the bonding electrons are most likely to be found in sausage-shaped regions above and below the bond axis of the bonded atoms.

Question 19

What is a tetrahedral angle?

Answer 19

A bond angle of 109.5 that results when a central atom forms four bonds directed toward the center of a regular tetrahedron.

Question 20

What is the VESPR theory?

Answer 20

Valence-shell electron-pair repulsion theory; because electron pairs repel. molecule adjust their shapes so that the valence electron pairs are as far apart as possible.

Question 21

What is hybridization?

Answer 21

The mixing of several atomic orbitals to form the same total number of equivalent hybrid orbitals.

Question 22

What are the VSEPR model and shapes?

Answer 22

1. Linear
2. Trigonal planar
3. Bent
4. Pyramidal
5. Tetrahedral

Question 23

What are the van der Waals forces?

Answer 23

The two weakest intermolecular attractions-dispersion interactions and dipole forces.

Question 24

What is an unshared pair?

Answer 24

A pair of valence electrons that is not shared between atoms.

Question 25

How many neighbors does a hexagonal close-packed arrangement have?

Answer 25

Twelve.

Question 26

Molecules consisting of two atoms.

Answer 26

Diatomic molecules.

Question 27

The chemical formula of a molecular compound?

Answer 27

Molecular formula.

Question 28

Do molecular compounds have high or low melting points?

Answer 28

Low

Question 29

Joins atoms held together by sharing electrons?

Answer 29

Covalent bonds.

Question 30

Two atoms held together by sharing one pair of electrons are joined by what?

Answer 30

Single covalent bond.

Question 31

Represents the covalent bonds as dashes and shows the arrangement of covalently bonded atoms.

Answer 31

Structural formula.

Question 32

Pair of valence electrons that is not shared between atoms.

Answer 32

Unshared pair.

Question 33

Bond that involves two pairs of shared pairs of electrons.

Answer 33

Double covalent bonds.

Question 34

Bonds that involves three shared pairs of electrons?

Answer 34

Triple covalent bond.

Question 35

A covalent bond in which one atom contribute both bonding electrons.

Answer 35

Coordinate covalent bond.

Question 36

A tightly bound group of atoms that has a positive or negative charge and behaves as a unit?

Answer 36

Polyatomic unit.

Question 37

The energy required to break the bond between two covalently bonded atoms?

Answer 37

Bond dissociation energy.

Question 38

Structures that occur when it is possible to draw two or more valid electron dot structures that have the same number of electron pairs for a molecule?

Answer 38

Resonance structures.

Question 39

What are three ways the octet rule can sometimes fail to be obeyed?

Answer 39

When the total number of valence electrons is an odd number, when molecules have less than a complete octet of electrons, when molecules have more than a complete octet of electrons.

Question 40

The quantum mechanical model of bonding assumes that atomic orbitals overlap to produce ______.

Answer 40

Molecular orbitals.

Question 41

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

Answer 41

Bonding orbital.

Question 42

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

Answer 42

Sigma.

Question 43

Produced when atomic orbitals overlap side by side?

Answer 43

Pi bond.

Question 44

What states that because the electron pairs repel, molecular shape adjusts so the valence-electron pairs are as far apart as possible?

Answer 44

VSEPR theory.

Question 45

The weakest of all molecular interactions, are caused by the motion of electrons.

Answer 45

Dispersion forces.

Question 46

Arrange the following in: order of increasing strength: dipole interactions, dispersion interactions, and hydrogen bonds.

Answer 46

Dispersions dipole hydrogen

Question 47

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

Answer 47

Network solid.

Question 48

A term used to describe the weakest intermolecular attractions; these include dispersion forces and dipole forces

Answer 48

Van der Waals forces.

Question 49

A molecular in which one end is slightly positive and the other end is slightly negative.

Answer 49

Polar molecule

Question 50

Bond in which a hydrogen covalently bonded to very electronegative atom is also weakly bonded to an unshared electron pair of another electronegative atoms.

Answer 50

Hydrogen bond.

Question 51

A molecule in which one end is slightly positive and the other end is slightly negative.

Answer 51

Polar molecule