Topic 2: bonding, structure, and properties of matter

Question 1

what is ionic bonding?

Answer 1

ionic bonding is the electrostatic attraction between positive and negative ions
it is a relatively strong connection

Question 2

how are ionic compounds held together?

Answer 2

• held together in a giant lattice
• regular structure that extends in all directions in a substance
• electrostatic attraction between positive and negative ions hold the structure together

Question 3

state the properties of ionic substances

Answer 3

• high melting and boiling point
• strong electrostatic forces between positively charged ions
• do not conduct electricity when solid (ions are in fixed proportions)
• conduct when molten or dissolved in water (ions are free to move)

Question 4

how are ionic compounds formed, explain in terms of MgO

Answer 4

reaction of a metal with a non-metal
electron transfer occurs - metal gives away its outer shell electrons to non-metals
Mg is in group II, so has 2 available outer shell electrons
O is in group VI, so can accept 2 electrons to get a full outer shell configuration
Mg becomes Mg2+ and O becomes o2-

Question 5

what is a covalent bond?

Answer 5

covalent bond is a shared pair of electrons between 2 atoms

Question 6

describe the structure and properties of simple molecular covalent substances

Answer 6

• do not conduct electricity
• small molecules
• weak intermolecular forces, therefore
• low melting and boiling point

Question 7

how do intermolecular forces change as the mass/size of the molecule increase

Answer 7

they increase
cause melting and boiling points to increase as well

Question 8

what are polymers

Answer 8

polymers are very large molecules with atoms linked by covalent bonds

Question 9

what are thermosoftening polymers

Answer 9

a special type of polymer
they melt/ soften when heated
there are no bonds between polymer chains
strong intermolecular forces ensure that the structure is solid at room temp
these forces are overcome by heating - polymer melts

Question 10

List the properties of giant covalent substances?

Answer 10

• solids, atoms covalently bonded together in a giant lattice
• high melting and boiling points
• strong covalent bonds
• mostly don’t conduct electricity (no delocalized electron)

Question 11

examples of giant covalent substances

Answer 11

diamond, graphite, silicon dioxide

Question 12

describe and explain the properties of allotropes of carbon:
Diamond

Answer 12

• four very strong covalent bonds for each carbon atom
• very hard (explanation: strong bonds)
• very high melting point (explanation: strong bonds)
• does not conduct electricity (explanation: no delocalised electrons)

Question 13

describe and explain the properties of allotropes of carbon:
fullerenes:

Answer 13

• hollow-shaped molecules
• based on hexagonal rings

Question 14

explain the buckminsterfullerne structure

Answer 14

-c60 has a spherical shape, a simple molecular structure

Question 15

describe and explain the properties of allotropes of carbon:
nanotubes

Answer 15

• cylindrical fullerene with a high length-to-diameter ratio
• high tensile strength (strong bonds)
• conductivity (delocalized electrons present)

Question 16

describe and explain the properties of allotropes of carbon:
graphene

Answer 16

a single layer of graphite

Question 17

describe and explain the properties of allotropes of carbon:
graphite

Answer 17

• 3 layers of covalent bonds for each carbon atom
• layers of hexagonal rings
• high melting point
• layers free to slide as weak intermolecular forces between layers: soft and can be used as a lubricant
• conduct thermal energy and electrical energy due to one delocalized electron per carbon atom

Question 18

what is metallic bonding?

Answer 18

forces of attraction between delocalized electrons and nuclei of metal ions

Question 19

describe the properties of metals

Answer 19

• high melting point and boiling point (explanation: strong forces of attraction)
• good conductors of heat and electricity (explanation: delocalized electron present)
• malleable, soft (explanation: layers of atoms can slide over each other whilst maintaining the attraction forces)

Question 20

what are alloys

Answer 20

mixture of metal with other elements

Question 21

why are alloys harder than pure metals?

Answer 21

different sizes of atoms distort the layers so they cannot slide over each other therefore alloys are harder than pure metals

Question 22

what is the melting and boiling point of simple covalent bonds?

Answer 22

loe due to weak intermolecular forces between molecules

Question 23

what is the conductivity when a solid of simple covalent bonds

Answer 23

poor, no ions to conduct

Question 24

what is the conductivity when molten of simple covalent bonds?

Answer 24

poor due to no ions to conduct

Question 25

what is the general description of simple covalent bonds?

Answer 25

mostly gases and liquids

Question 26

what is the boiling point and melting? point of ionic bonds

Answer 26

high due to a giant lattice of ions with strong forces between oppositely charged ions

Question 27

what are the melting and boiling points of giant covalent bonds?

Answer 27

high because of many strong covalent bonds between atoms in giant structure

Question 27

what is the conductivity when a solid of ionic bonding

Answer 27

poor due to ions not being able to move

Question 28

what is the conductivity when molten ionic compounds?

Answer 28

good due to ions are free to move

Question 29

what is the general description of ionic bonds?

Answer 29

crystalline solid

Question 30

what is the conductivity when a solid of giant covalent bonds

Answer 30

Diamond and sand: poor, because electrons cannot move graphite: good as they have delocalized electrons between layers can move through the structure

Question 31

what is the conductivity when molten of giant covalent bonds

Answer 31

poor

Question 32

general description of giant covalent bonds

Answer 32

solids

Question 33

boiling and melting point of metallic bonds

Answer 33

high due to strong electrostatic forces between positive ions and delocalized electrons

Question 34

conductivity when solid of metallic bonding

Answer 34

good as delocalized electrons are free to move through the structure

Question 35

what is the conductivity of molten metallic bonds?

Answer 35

good

Question 36

what is the general description of metallic bonds?

Answer 36

shiny metal solids

Question 37

what are the limitations of the simple model?

Answer 37

there are no forces between spheres and atoms, molecules and ions are solid spheres - this is not true

Question 38

what does the amount of energy needed to change state from solid to liquid or liquid to gas depending on

Answer 38

the strength of the forces between the particles of the substance stronger forces means higher melting/boiling point so more energy will be needed

Question 39

what are the 3 states of matter?

Answer 39

solid, liquid, or gas

Question 40

what is nanoscience

Answer 40

science that studies particles that are 1-100nm in size

Question 41

state the uses of nanoparticles

Answer 41

- medicine - electronics - deodorants - sun creams

Question 42

why are nanoparticles good for sun cream?

Answer 42

better skin coverage and more effective protection against cell damage as it has a high surface area:volume ratio

Question 43

diameter of fine particles and give an example

Answer 43

100-2500nm soot

Question 44

diameter of coarse particles

Answer 44

2500-10(5) nm diameters

Question 45

why do nanoparticles have high properties different from those for the same materials in bulk?

Answer 45

high surface area:volume ratio

Question 46

name 3 types of chemical bond

Answer 46

ionic, metallic, covalent

Question 47

define ionic bonding

Answer 47

electrostatic attraction between oppositely charged ions

Question 48

define covalent bonding

Answer 48

Electrostatic attraction between a positive nucleus and a shared pair of negative electrons.

Question 49

Define metallic bonding.

Answer 49

Electrostatic attraction between positively charged ions and delocalised electrons.

Question 50

What type of atoms form ionic bonds?

Answer 50

Non-metals with metals.

Question 51

What type of atoms form covalent bonds?

Answer 51

Non-metals only.

Question 52

What type of atoms form metallic bonds?

Answer 52

metals only

Question 53

What happens to the outer shell electrons when ionic bonds form?

Answer 53

Electrons are always transferred from the metal to the non-metal.

Question 54

What happens to the metal atoms in ionic bonding?

Answer 54

They lose their outer shell electrons to have a full shell and form a positively charged ion.

Question 55

How can you find out the size of the positive charge on a metal ion?

Answer 55

The group number except for transition metals, their charge is shown by Roman numerals.

Question 56

What happens to the non-metal atoms in ionic bonding?

Answer 56

They gain outer shell electrons to fill their shell and become negatively charged ions.

Question 57

How can you find out the size of the negative charge on a non-metal ion?

Answer 57

8 minus the group number is the size of the negative charge.

Question 58

What charge will a Group 1 metal have?

Answer 58

1

Question 59

what charge will a group 2 metal have?

Answer 59

2

Question 60

what charge will a group 3 metal have?

Answer 60

3

Question 61

what charge will a group 7 non-metal have

Answer 61

-1

Question 62

what charge will a group 6 non-metal have

Answer 62

-2

Question 63

what charge will a group 5 non-metal have

Answer 63

-3

Question 64

why do atoms become ions

Answer 64

to attain a full outer-shell of electrons

Question 65

how do you describe ionic bonding in terms of electron transfer

Answer 65

State what has happened to the electrons in the metal and then the non-metal. State the charges on the ions that form. Give the formula of the ionic compound formed. State why they transfer electrons.

Question 66

name the first 3 halide ions

Answer 66

fluoride, chloride, and bromide

Question 67

Name and write the formula of the GCSE molecular positive ion

Answer 67

Ammonium, NH4+.

Question 68

Name and write the formula of the GCSE molecular 1- ions.

Answer 68

Hydroxide, OH- and nitrate, NO3-.

Question 69

Name and write the formula of the GCSE molecular 2- ions.

Answer 69

Sulfate, SO42- and carbonate, CO32-.

Question 70

Name and write the formula of the GCSE molecular 3- ion.

Answer 70

Phosphate, PO43-.

Question 71

Describe how you can work out the molecular formula of an ionic compound

Answer 71

Label each ions charge. Assign each ion the number of the oppositely charged ion.

Question 72

Describe how you should draw a covalent molecule.

Answer 72

Draw the outer electron shell of the atom present in the smallest amount. Draw overlapping circles for the other atoms present. Write x and o in the overlaps. Fill up any missing electrons.

Question 73

Describe how you should draw a metallic element.

Answer 73

Draw a box with dashed line circles inside, arrange them in rows, write a + in each circle, label the empty space in the box as delocalised electrons.

Question 74

At what point does a solid melt?

Answer 74

its melting point

Question 75

At what point does a gas condense?

Answer 75

its boiling point

Question 76

What determines the melting and boiling point of a material?

Answer 76

The strength of the forces between the particles.

Question 77

How can you work out the state of a material at a specific temperature?

Answer 77

Put the melting point and boiling point at two ends of a continuum, label all temperatures to the left of the melting point as solid, all to the right of the boiling point as gases. Liquids are in between.

Question 78

Write the names and symbols of all 4 state symbols.

Answer 78

Solid (s), liquid (l), gas (g) and aqueous (aq).

Question 79

Can an individual particle have a melting point?

Answer 79

No because it will not have the same properties as the bulk material and no bonds.

Question 80

State the structure of an ionic compound.

Answer 80

giant ionic lattice

Question 81

State the structure of a covalent compound.

Answer 81

Small molecule.

Question 82

Describe the melting points of small molecules.

Answer 82

weak

Question 83

What is the typical state of a small molecule?

Answer 83

liquid or gas