chapter 4

Question 1

between what elements does ionic bonding occur?

Answer 1

metal and non-metal

Question 2

between what elements does covalent bonding occur?

Answer 2

non-metals

Question 3

what does isoelectronic mean

Answer 3

species with the same number of electrons

Question 4

what happens in ionic bonding ?

Answer 4

electrons are transferred from one atom to another to form positive and negative ions

Question 5

how are cations formed?

Answer 5

metals loosing an electron

Question 6

how are anions formed?

Answer 6

non- metals gaining electrons

Question 7

what determines the number of electrons lost or gained?

Answer 7

electron configuration

Question 8

why does ionic bonding occur?

Answer 8

electrostatic attraction between oppositely charged ions

Question 9

what is a giant structure?

Answer 9

no individual molecules

Question 10

physical properties of ionic compounds?

Answer 10

high boiling points, low volatility, dont conduct electricity (when solid), soluble in water

Question 11

what is volatility

Answer 11

how readily a substance evaporates

Question 12

why do ionic compounds have low volatility?

Answer 12

strong electrostatic forces

Question 13

how is a covalent bond formed?

Answer 13

electrostatic attraction between a shared pair of electrons and the positively charged nuclei

Question 14

what happens when you add more bonds (double, triple)

Answer 14

bond strength increases

Question 15

what is longer single bond or double bond

Answer 15

single bond

Question 16

what is electronegativity

Answer 16

measure of the attraction of an atom in a molecule for the electron pair in the covalent bond

Question 17

how does bonding polarity occur

Answer 17

difference in electronegativities of the bonded atoms

Question 18

why do noble gases not have electronegativity values

Answer 18

because they do not form compounds

Question 19

what bonds will atoms with highly different electronegativities form

Answer 19

ionic

Question 20

what does a lewis structure show?

Answer 20

all the valence electrons in a covalently bonded species

Question 21

what is the octet rule

Answer 21

atoms in a covalence bond have a tendency to have a shell of 8 electrons

Question 22

what is a coordinate bond

Answer 22

a coordinate covalent bond is a type of covalent bond in which both electrons come from the same atom

Question 23

how is a covalent bond shown?

Answer 23

an arrow

Question 24

what are some exceptions to the octet rule?

Answer 24

Be and B

Question 25

when do resonance structures form?

Answer 25

when there is more than one possible position for a double bond in a molecule

Question 26

what determines the shape of a molecule?

Answer 26

VSEPR theory (valence shell electron pair repulsion)

Question 27

what is the VSEPR theory?

Answer 27

paris of electrons in the valence shell of an atom repel each other and will therefore take up positions in space to minimise the repulsions

Question 28

what is the shape and bond angle of a molecule with 2 electron domains?

Answer 28

linear, 180

Question 29

what is the shape and bond angle of a molecule with 3 electron domains?

Answer 29

trigonal planar, 120

Question 30

what is the shape and bond angle of a molecule with 4 electron domains?

Answer 30

tetrahedral, 109.5

Question 31

what is an electron domain?

Answer 31

a pair of electrons

Question 32

what is the order of repulsion strength for pairs of electrons?

Answer 32

lp-lp>lp-bp>bp-bp

Question 33

what is the basic shape

Answer 33

arrangement of the electrons around the central atom

Question 34

what is a polar bond

Answer 34

one end is slightly less positive than the other (difference in electronegativity)

Question 35

if individual bonds are polar does that make the molecule polar

Answer 35

no, the symmetry of the molecule may cause the dipole moment of individual molecules to cancel out

Question 36

what are allotropes

Answer 36

different forms of the same element

Question 37

what is the structure of diamond

Answer 37

giant covalent, no individual molecules, four carbon bonds, tetrahedral array

Question 38

properties of diamond?

Answer 38

high melting and boiling point (covalent bonds), doesn't conduct electricity, not soluble in water (forces between atoms are too strong)

Question 39

what is the structure of graphite ?

Answer 39

giant covalent structure, each carbon is linked to 3 others in trigonal planar, single layers connected with london forces

Question 40

what are properties of graphite?

Answer 40

conducts electricity, not soluble in water

Question 41

what is graphene?

Answer 41

a single layer of graphite

Question 42

what is the structure of C60 fullerene?

Answer 42

molecule, covalent bonds and london forces

Question 43

properties of fullerene?

Answer 43

insoluble in water, soluble in some organic substances, doesnt conduct electricity, forms 3 bonds

Question 44

give examples of intermolecular forces (van der waal)?

Answer 44

London dispersion forces, dipole-dipole forces and hydrogen bonding

Question 45

what are intermolecular forces?

Answer 45

forces between molecules

Question 46

what are intramolecular forces?

Answer 46

forces within a molecule

Question 47

how are london forces made?

Answer 47

temporary dipole-induced interactions

Question 48

what makes london forces become stronger?

Answer 48

as relative molecular mass increases

Question 49

what are hydrogen bonds?

Answer 49

interaction between an electronegative atom and a hydrogen atom

Question 50

what are the requirements for hydrogen bonding?

Answer 50

H atom is attached to a very electronegative atom: N, O or F

Question 51

what forces are broken down when covalent molecular substances are melted or boiled?

Answer 51

intermolecular forces, covalent bonds are NOT

Question 52

what are the van der waal forces from weakest to strongest?

Answer 52

london < permanent dipol-dipole < hydrogen

Question 53

what is solubility in intermolecular forces?

Answer 53

a substance will dissolve in a solvent if the intermolecular forces in the solute and solvent are similar

Question 54

what are the requirements for a substance to have hydrogen bonding?

Answer 54

soluble in water, because they are able to hydrogen bond to the water

Question 55

what is metallic bonding?

Answer 55

electrostatic attraction between the positive ions in the lattice and the delocalised electrons

Question 56

what is the structure of metals?

Answer 56

a regular lattice arrangement of positive ions surrounded by a 'sea' of delocalised electrons

Question 57

why are metals ductile?

Answer 57

non-directionality of the bonding

Question 58

what are alloys?

Answer 58

alloys are homogenous mixtures of two or more metals, or of a metal with a non-metal

Question 59

why are alloys stronger than pure metals?

Answer 59

because the atom sizes are different

Question 60

what determines the strength of a metallic bond?

Answer 60

charge of the ion and radius of the metal ion