Chapter 6 - Claire

Question 1

What Δ EN values create an ionic bond?

Answer 1

1.7 to 3.3

Question 2

What Δ EN values create a covalent bond?

Answer 2

0 to 1.7

Question 3

Where is atomic radius the largest?

Answer 3

Bottom left of the periodic table

Question 4

Are cations smaller or larger than the neutral atom?

Answer 4

Smaller

Question 5

Are anions smaller or larger than the neutral atom?

Answer 5

Larger

Question 6

Def. the net positive charge experienced by an electron in a multi electron atom, representing less than the full nuclear charge as inner electrons repel outer electrons, offsetting some of the nucleus’s inward pull(I.e. shielding effect)

Answer 6

Effective nuclear charge

Question 7

Def. the repulsive action of inner core electrons in outer valence electrons, effectively reducing the nucleus’s inward pull, causing the atom to increase in size

Answer 7

Shielding effect

Question 8

Coulomb’s law states that the _______ of force depends directly on the amount of ____________

Answer 8

Strength, electrostatic charge

Question 9

Which two elements have no shielding effect?

Answer 9

Hydrogen and helium

Question 10

What are the four types of charge?

Answer 10

1. Proton-proton repulsion
2. Neutron-proton attraction (residual strong force)
3. Electron-electron repulsion
4. Nucleus-electron attraction

Question 11

Def. an expression of the size of an atom, representing the typical distance from the center of its nucleus to the boundary of its electron cloud

Answer 11

Atomic radius

Question 12

Def. an estimate of the size of an atom, based on half the distance between covalently bonded atoms

Answer 12

Covalent radius

Question 13

Def. an estimate of an the size of a metal atom based on half the distance between the nuclei of adjacent atoms in a metal lattice

Answer 13

Metallic radius

Question 14

What affects an electron cloud/ an atoms size?

Answer 14

1. Number of occupied shells

2. Amount and type of charge

Question 15

Def. predictable and regular patterns of cyclical change in elemental properties throughout the periodic table, moving either vertically or horizontally

Answer 15

Periodic trends

Question 16

Def. the amount of energy required to remove the most loosely held electron from a gaseous atom to form a cation, or from a cation to increase its positive charge

Answer 16

Ionization energy

Question 17

Where are electrons held the most loosely?

Answer 17

Bottom right of the periodic table

Question 18

Def. a chemical property that describes an atom’s (or a group of atoms’) ability to attract electrons towards itself

Answer 18

Electronegativity

Question 19

Def. the change in energy when an atom gains an electron to form an anion, or when an anion gains another electron, increasing its negative charge

Answer 19

Electron affinity

Question 20

The higher the electronegativity, the higher the ____________

Answer 20

Electron affinity

Question 21

def. A numerical value representing the difference in the electronegativities of two atoms

Answer 21

ΔEN

Question 22

def. A covalent bond between non-metal atoms with the same electronegativities, where
electron sharing is equal between them

Answer 22

Nonpolar covalent bond

Question 23

Are electrons ever transferred to a different atom?

Answer 23

No, they only effectively transfer because there is always some sort of electronegativity

Question 24

def. A covalent bond between two non-metal atoms in which electron sharing is sufficiently
unequal that the bond displays significant and meaningful ionic nature

Answer 24

Polar covalent bond

Question 25

Where is the electron sharing is equal or nearly equal between the atoms and the bond has predominantly covalent character with little to no ionic character?

Answer 25

Nonpolar bonds

Question 26

Where is the electron sharing is disproportionately uneven enough that the bond has predominantly ionic character, with very little covalent character?

Answer 26

ionic bonds

Question 27

def. The non-integer charge values at the ends of a polar covalent bond, due to the uneven distribution of electron density within the bond

Answer 27

Partial ionic charges (δ+, δ–)

Question 28

Where is the electron sharing is uneven enough that | the covalent bond has some ionic nature – more than a nonpolar bond, but less than an ionic?

Answer 28

polar bonds

Question 29

what Δ EN values form a polar bond?

Answer 29

0.4-1.7

Question 30

what Δ EN values form a non-polar bond?

Answer 30

0-0.4

Question 31

def. A simplified diagram that communicates molecular structure using: ▪ An element’s symbol to represent its nucleus and core electrons ▪ Dots to represent any nonbonding electrons in the valence shells ▪ Lines to represent the pairs of bonding electrons in chemical bonds

Answer 31

Lewis structure

Question 32

What are Lewis structures of individual atoms called?

Answer 32

electron dot structures

Question 33

when orbitals hybridize they become ________

Answer 33

equivalent

Question 34

def. describes an atom's combining power, often in terms of how many chloride anions it can ionically bond with

Answer 34

valency

Question 35

for metals, valency represents how many electrons it will _______

Answer 35

lose

Question 36

for non-metals, valency represents how many electrons it will _______

Answer 36

gain

Question 37

Apart from how many electrons a non-metal will gain, what does valency represent for non-metals?

Answer 37

how many covalent bonds it will form

Question 38

the lewis structure of _______ compounds show the component ions and the ratio between them

Answer 38

ionic

Question 39

for the lewis structures of ionic compounds, you must surround the ions with _______ brackets and ___________

Answer 39

square, superscript to represent their ionic charges

Question 40

ionic compounds exist in what way?

Answer 40

ionic crystal lattices

Question 41

covalent compounds exist in what way?

Answer 41

as separate and distinct molecules

Question 42

Valence electrons can be either _______ or _______

Answer 42

bonding or non-bonding

Question 43

def. any pair of valence electrons that are non-bonding, as atoms don't share them with other atoms

Answer 43

lone pair

Question 44

lone pairs may _______ or _______ because of bond formation

Answer 44

form or disperse

Question 45

hydrogen obeys the ____ rule in molecules

Answer 45

duet

Question 46

def. an observational rule in chemistry that says the valence shells of the first-period elements hydrogen and helium can hold a maximum of two electrons, never more

Answer 46

duet rule

Question 47

def. An observational rule of thumb in chemistry that says main-group elements from periods 2 to 7 seek to have eight electrons in their valence shell

Answer 47

octet rule

Question 48

What are the exceptions to the octet rule?

Answer 48

Boron, Beryllium, Aluminium, Hydrogen and Helium

Question 49

What periods can exceed the octet rule?

Answer 49

Periods 3-7

Question 50

In a Lewis structure, for binary compounds which element is usually the central atom?

Answer 50

the one with the lower electronegativity

Question 51

def. Covalent bonding between two atoms who share more than two electrons

Answer 51

Multiple bond

Question 52

def. A configuration of elements from periods 3 through 7, in which their valence shells expand past eight electrons as the central atom, as they can incorporate d orbitals

Answer 52

expanded octet

Question 53

when a molecule's central atom takes on more than eight electrons, what do we call the molecule?

Answer 53

Hypervalent molecule

Question 54

def. Different, but equivalent Lewis structures of the same molecule, showing all the possible double bond locations, connected by a double-headed arrow

Answer 54

resonance structures

Question 55

def. Electrons in a molecule, ion or solid metal that aren’t associated with a single atom or covalent bond, allowing them to be co-valent to more than two atoms

Answer 55

Delocalized electrons

Question 56

When atoms share electrons unevenly enough that the the bond takes on ionic character, the atoms develop _________

Answer 56

partial charges

Question 57

the _____ electronegative atom gains electron density and develops a partial negative charge δ–

Answer 57

more

Question 58

the ______ electronegative atom loses the electron density, and develops a partial positive charge δ+

Answer 58

less

Question 59

def. describes the separation of opposite charge

Answer 59

electric dipole

Question 60

def. A vector quantity that expresses a bond’s polarity, showing the separation of opposing charges (an electric dipole), and the directionality of that separation (a moment)

Answer 60

bond dipole moment

Question 61

def. o A molecule that has an overall, or net dipole moment, because of its bond polarities and its molecular geometry

Answer 61

polar molecule

Question 62

def. A vector quantity expressing a molecule’s overall polarity, being the net dipole moment resulting from the vector addition of the molecule’s individual bond dipole moments

Answer 62

molecular dipole moment

Question 63

when can a molecule be polar?

Answer 63

A molecule can only be polar if it contains polar bonds and | is asymmetrical, in either shape, composition or both

Question 64

def. Attractive forces that exist within a molecule or compound, holding the atoms together

Answer 64

Intramolecular forces

Question 65

def. Forces, mainly attractive, that exist between molecules and neighbouring particles, be they other molecules, atoms or ions

Answer 65

Intermolecular forces

Question 66

def. The attractive force that exists between the partial positive charge of one polar molecule and the partial negative charge of another

Answer 66

dipole-dipole force

Question 67

dipole-dipole forces exist between polar molecules that have ______ molecular dipole moments

Answer 67

permanent

Question 68

``` def. An electrostatic attraction that forms between the partially positive hydrogen in a highly polarized bond (usually H–N, H–O and H–F) and the negative lone pair on a nearby atom ▪ Stronger than a typical dipole-dipole interaction because it has some covalentbond character of electron sharing ```

Answer 68

Hydrogen bond

Question 69

In polar molecules, quantum mechanical uncertainty affects the ________ of the molecular dipole moment

Answer 69

strength

Question 70

In nonpolar molecules, quantum mechanical uncertainty affects the ________ of a molecular dipole

Answer 70

existence

Question 71

def. A weakly attractive force that forms when nonpolar molecules gain temporary dipole moments

Answer 71

London dispersion force