Chapter 8-Finals

Question 1

Covalent bonds definition

Answer 1

involve the sharing of electrons between atoms

Question 2

Why do atoms form covalent bonds

Answer 2

Because the atoms want to have a complete octet

Question 3

Are there ions involved in covalent bonds?

Answer 3

NO

Question 4

Covalent bonds tend to form between what type of atom?

Answer 4

Tend to form between the atoms of two or more nonmetals

Question 5

Molecule definition

Answer 5

2 or more nonmetals held tightly together by a covalent bond

Question 6

Diatomic molecule

Answer 6

a molecule consisting of 2 atoms

Question 7

Name some important diatomic molecules

Answer 7

H2, N2, O2, Br2, I2, F2, Cl2

Question 8

Molecular compound

Answer 8

A compound made up of nonmetals

Question 9

Do molecular compounds tend to have low or high melting and boiling points?

Answer 9

Tend to have low melting and boiling points

Question 10

What state do many molecular compounds take on at room temperature?

Answer 10

Many are gasses or liquids at room temperature

Question 11

Molecular formula definition

Answer 11

Chemical formula of a molecular compound

Question 12

What does a molecular formula show

Answer 12

Shows the kinds and numbers of atoms present in a molecule of a substance

Question 13

Does a molecular formula provide information about a molecule’s structure?

Answer 13

It doesn’t provide information about a molecule’s structure

Question 14

Are subscripts always in the lowest whole number ratios in a molecular formula?

Answer 14

Subscripts aren’t necessarily in the lowest whole number ratios

Question 15

Empirical formula definition

Answer 15

when the subscripts are in lowest whole number ratios

Question 16

Are all molecular compounds composed of atoms of two or more different elements?

Answer 16

Yes

Question 17

Do all compounds contain molecules?

Answer 17

No

Question 18

Do any elements exist as molecules?

Answer 18

Yes

Question 19

Are most molecular compounds composed of two or more nonmetallic elements?

Answer 19

Yes

Question 20

Do atoms in molecular compounds share electrons?

Answer 20

Yes

Question 21

Do molecular compounds tend to have higher or lower boiling points than ionic compounds?

Answer 21

Lower

Question 22

Single covalent bond

Answer 22

the sharing of one pair of electrons between two atoms

Question 23

Double covalent bond

Answer 23

the sharing of two pairs of electrons between two atoms

Question 24

Triple covalent bond

Answer 24

the sharing of three pairs of electrons between two atoms

Question 25

What do structural formulas show

Answer 25

They show the kind and number of atoms present in a molecule of a substance, and also the arrangement of the atoms

Question 26

In a structural formula, what is used to represent covalent bonds?

Answer 26

Dashes

Question 27

In structural formulas, what are electrons not involved in bonding called?

Answer 27

Electrons not involved in bonding are called lone pairs or nonbonding pairs

Question 28

Nonpolar covalent bond definition

Answer 28

electrons are shared equally between the atoms

Question 29

What causes electrons to be shared equally between the atoms in a nonpolar covalent bond?

Answer 29

Because both atoms have similar electronegativities

Question 30

Polar covalent bond (polar bond) definition

Answer 30

Electrons are not shared equally between the atoms

Question 31

What causes electrons to not be shared equally between the atoms in a polar covalent bond?

Answer 31

Because one of the atoms is more electronegative than the other

Question 32

What else besides electronegativity can contribute to the polarity of a molecule?

Answer 32

The shape of a molecule can also contribute to its polarity

Question 33

What must a polar molecule have?

Answer 33

Must have at least one polar bond.

Question 34

What are the effects of polar molecules having polar bonds?

Answer 34

This gives the molecule regions of slightly negative and slightly positive charge

Question 35

Example of a polar molecule

Answer 35

Water

Question 36

Do nonpolar molecules always have polar bonds?

Answer 36

May or may not have a polar bond

Question 37

What ultimately determines whether a molecule with a polar bond is polar?

Answer 37

The shape of the molecule ultimately determines whether a molecule with a polar bond is itself polar.

Question 38

Nonpolar molecule examples

Answer 38

Methane, carbon dioxide

Question 39

Intermolecular forces of attraction

Answer 39

Forces that exist between molecules and are weaker than either ionic or covalent bonds.

Question 40

Give 2 examples of van der walls forces

Answer 40

Dispersion forces and dipole interactions.

Question 40

What do intermolecular forces of attraction help determine?

Answer 40

They help to determine whether a molecular compound is a solid, liquid or gas at a given temperature

Question 41

What causes dispersion forces

Answer 41

These are caused by the motion of electrons

Question 42

What is the weakest of all molecular interactions

Answer 42

Dispersion forces

Question 43

What causes dispersion forces to get stronger

Answer 43

Generally, the strength of these forces increases as the number of electrons in a molecule increases

Question 44

When do dipole interactions occur?

Answer 44

Occur when polar molecules are attracted to one another

Question 45

Between what regions of the polar molecules does the attraction of dipole interactions occur?

Answer 45

The attraction occurs between the delta+ region of one molecule and the delta- region of a second molecule

Question 46

What is hydrogen bonding?

Answer 46

A type of dipole-dipole interaction

Question 47

What is the strongest of the intermolecular forces

Answer 47

Hydrogen bonding

Question 48

Between what type of molecules does hydrogen bonding exist?

Answer 48

Exists between water molecules

Question 49

Hydrogen bonding occurs between the ___ atom of one molecule and a very _________ _______________ of a second molecule.

Answer 49

Is between the H atom of one molecule and a very electronegative element of a second molecule

Question 50

Does hydrogen bonding always occur between 2 different molecules?

Answer 50

No, it may also occur between different regions of the same molecule.

Question 51

Electron dot structure

Answer 51

A depiction of valence electrons around the symbol of an element

Question 52

Octet rule

Answer 52

Atoms in most compounds tend to achieve the electron configuration of a noble gas

Question 53

Valence electron

Answer 53

An electron in the highest occupied energy level of an atom

Question 54

In forming chemical bonds, atoms tend to attain what electron configuration?

Answer 54

The electron configuration of noble gas atoms.