Chemistry 2

Question 1

What are the three types of strong chemical bond?

Answer 1

Ionic, covalent, metallic.

Question 2

What particles are found in:
Ionic bonding
Covalent bonding
Metallic bonding

Answer 2

Ionic bonding oppositely charged ions.

Covalent bonding atoms which share electrons.

Metallic bonding Atoms which share delocalised electrons.

Question 3

Which type of bonds occurs when metals combine with non-metals?

Answer 3

Ionic.

Question 4

What type of bonding occurs in carbon dioxide? Why?

Answer 4

Covalent; two non-metals.

Question 5

What type of bonding occurs in alloys?

Answer 5

Metallic.

Question 6

What happens to the electrons in ionic bonding?

Answer 6

Transferred.

Question 7

What electronic structure do the ions produced by metals in Groups 1 and 2 and the non-metals in Groups 6 and 7 have?

Answer 7

Electronic structure of a noble gas.

Question 8

What is the link between the charge number on the ions in groups 1, 2 and 3 and their group number ?

Answer 8

Charge number is same as Group number.

Question 9

What is an ionic compound?

Answer 9

Giant structure of ions.

Question 10

How are ionic compounds held together?

Answer 10

Strong electrostatic forces of attraction; between oppositely charged ions.

Question 11

Why is the ball and stick model not an accurate representation of the structure of an ionic compound?

Answer 11

Does not accurately depict the millions of ions in the lattice. The ions should touch each other/ there are no gaps between the ions.

Question 12

How are strong covalent bonds formed?

Answer 12

Atoms share pairs of electrons.

Question 13

What are the three types of structure that can be formed by covalent bonding?

Answer 13

Small molecules, very large molecules, giant covalent molecules.

Question 14

What are polymers an example of?

Answer 14

Very large molecules.

Question 15

What type of structure do the following covalently bonded substances have?

Water H2O

Silicon dioxide SO2

Diamond C

Poly(ethene) .

Answer 15

Water H2O Small covalent.

Silicon dioxide SO2 Giant covalent.

Diamond C Giant covalent.

Poly(ethene) Very large molecule.

Question 16

What are the limitations of using dot and cross diagrams to represent covalent bonds?

Answer 16

It shows the electrons differently, when they are the same and it does not show the bond angles or shape of the molecule.

Question 17

How are atoms arranged in a metal?

Answer 17

Giant structures of atoms, arranged in a regular pattern, delocalised electrons.

Question 18

Why are metallic bonds so strong?

Answer 18

Sharing of delocalised electrons.

Question 19

Describe the arrangement of particles in a metal.

Answer 19

Atoms arranged neatly in rows; sea of delocalised electrons.

Question 20

Why are the particles that make up a metal described as positively charged?

Answer 20

The metal atoms lose outer shell electrons and therefore there
are more protons (+) than electrons (−).

Question 21

What are delocalised electrons?

Answer 21

They are free-moving electrons within structure; not associated with a particular atom.

Question 22

What are the three states of matter?

Answer 22

Solid, liquid, gas.

Question 23

What is used to represent particles in the simple particle model?

Answer 23

Small solid spheres.

Question 24

What takes place at the melting point?

Answer 24

Melting and freezing.

Question 25

What takes place at the boiling point?

Answer 25

Boiling and condensing.

Question 26

What factor affects the amount of energy needed to change state?

Answer 26

Forces between molecules.

Question 27

In chemical equations what symbols are used to show the states of matter?

Answer 27

``` Solid = (s); liquid = (l); gas = (g); aqueous = (aq) ```

Question 28

In what state of matter do particles have the most energy?

Answer 28

Gas.

Question 29

What would eventually happen to a gas if pressure is increased?

Answer 29

Condense into a liquid.

Question 30

Explain the limitations of the particle model.

Answer 30

No forces, particles are shown as spheres, spheres are solid.

Question 31

Describe the structure of ionic compounds.

Answer 31

Regular, giant ionic lattice.

Question 32

Why do ionic compounds have high melting and boiling points?

Answer 32

Strong electrostatic forces of attraction between ions.

Question 33

Why can ionic compounds conduct electricity when melted or dissolved in water?

Answer 33

Ions are free to move, carry the charge.

Question 34

What state of matter are small molecules normally found in?

Answer 34

Gas or liquid.

Question 35

Why do small molecules have low melting and boiling points?

Answer 35

Weak forces between molecules/ intermolecular forces.

Question 36

What happens to the melting and boiling points as small molecules get bigger? Why?

Answer 36

Increases, intermolecular forces get bigger.

Question 37

Why don’t small molecules conduct electricity?

Answer 37

Do not have an overall electric charge.

Question 38

What are polymers?

Answer 38

Very large molecules made of repeating units.

Question 39

How are the atoms in a polymer linked together?

Answer 39

Strong covalent bonds.

Question 40

Why are polymers normally solid at room temperature?

Answer 40

Intermolecular forces relatively strong.

Question 41

Give an example of a giant covalent structure.

Answer 41

Diamond, graphite, silicon dioxide.

Question 42

Why do giant covalent structures have very high melting and boiling points?

Answer 42

Strong covalent bonds must be broken.

Question 43

Why do most metals have high melting and boiling points?

Answer 43

Strong metallic bonding.

Question 44

How are atoms arranged in pure metals?

Answer 44

Layers.

Question 45

What is an alloy?

Answer 45

Mixture of two elements, one of which is a metal.

Question 46

Why do we use alloys, rather than pure metals, for many uses?

Answer 46

They are harder as the layers are distorted.

Question 47

Why are metals good conductors of electricity?

Answer 47

Electrical charge carried by delocalised electrons.

Question 48

What is thermal energy?

Answer 48

Heat energy.

Question 49

Why are metals good conductors of thermal energy?

Answer 49

Energy is transferred by delocalised electrons.

Question 50

In a diamond, how many covalent bonds does each carbon make?

Answer 50

4

Question 51

Diamond does not conduct electricity. Why?

Answer 51

No delocalised electrons.

Question 52

Name 2 other properties of diamond.

Answer 52

Hard, very high melting point.

Question 53

In graphite, how many covalent bonds does each carbon make?

Answer 53

3

Question 54

Describe the structure of graphite.

Answer 54

Layers of hexagonal rings.

Question 55

Why is graphite soft?

Answer 55

Layers can slide over each other, weak forces between layers, no covalent bonds between layers.

Question 56

Why does graphite conduct electricity?

Answer 56

Each carbon has one delocalised electron.

Question 57

How is graphite similar to metals?

Answer 57

It contains delocalised electrons.

Question 58

What is graphene?

Answer 58

Single layer of graphite, 1 atom thick.

Question 59

What are fullerenes?

Answer 59

Molecules of carbon atoms with hollow shapes.

Question 60

What was the first fullerene to be discovered?

Answer 60

Buckminsterfullerene.

Question 61

What are carbon nanotubes?

Answer 61

Cylindrical fullerenes.

Question 62

What are carbon nanotubes useful for?

Answer 62

Electronics, nanotechnology and materials.

Question 63

What does nanoscience refer to?

Answer 63

Structures that are 1-100nm in size, a few hundred atoms.

Question 64

What are nanoparticles?

Answer 64

Smaller than fine particles.

Question 65

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

Answer 65

They have a high surface area to volume ratio. Smaller quantities are needed to be effective.

Question 66

Name 5 uses of nanoparticles.

Answer 66

Medicine, electronics, cosmetics, sunscreens, deodorants, catalysts.

Question 67

What is another name for an electron shell?

Answer 67

Orbital

Question 68

What are the most outer electrons called?

Answer 68

Valance electrons.

Question 69

Define Ductile.

Answer 69

Can be drawn into wires.

Question 70

Define Malleable.

Answer 70

Can be hammered into shapes.

Question 71

Fluorine is a non-metal. A fluorine atom has nine electrons. In terms of electrons, what happens when fluorine atoms react?

Answer 71

They gain an electron (1) to become a negative ion.

Question 72

Why are the Noble gases unreactive?

Answer 72

Very stable due to full outer shells.

Question 73

Explain how the positions of the elements in the periodic table are linked o the electronic structure of their atoms.

Answer 73

Atoms in the same group have the same number of electrons in their outer shells/energy levels.

Question 74

What is the trend of reactivity for group 1 elements?

Answer 74

the reactivity increases as you go down.

Question 75

What elements are in the halogens or noble gases?

Answer 75

Fluorine, chlorine, bromine.

Question 76

List 6 basic facts about Halogens.

Answer 76

1. Halogens are non-metals. 2. Halogens are found in group 7 of the periodic table. 3. They react with metals to from IONIC compounds w/ charge of -1. 4. From molecular compounds with non-metallic elements. 5. They exist as diatomic molecules. 6. A more reactive Halogen can replace a less reactive Halogen from an aqueous solution of its salt.

Question 77

As we go down group 7.. what trends increases or decreases?

Answer 77

``` The reactivity increases. The boiling point increases. The relative molecular mass increases. The conduction of electricity heat decreases. The density increases. ```

Question 78

What is a Mixture?

Answer 78

Mixture consists of two or more elements or compounds NOT chemically combined together. The chemical properties of each substance in the mixture are unchanged.

Question 79

What is Chromatography?

Answer 79

Chromatography is a physical method of separating a mixture of soluble substances.

Question 80

What is Chromatography used for?

Answer 80

Chromatography is a method used by scientists for separating organic and inorganic compounds so that they can be analyzed and studied.

Question 81

Why do the inks separate in chromatography?

Answer 81

The separation depends on how soluble the chemical is in the solvent and how strongly the chemical is attracted to the paper.

Question 82

What is the mass number in an element.

Answer 82

number of protons=+number of neutrons.

Question 83

Define Solvent.

Answer 83

The liquid in which a solute dissolves.

Question 84

Define Solute

Answer 84

The substance that dissolves in a liquid to form a solution.

Question 85

Define Solution.

Answer 85

It is the mixture formed when a solute has dissolved in a solvent.

Question 86

Define Soluble.

Answer 86

Describes a substance that will dissolve.

Question 87

Define Insoluble.

Answer 87

It describes a substance that will not dissolve.

Question 88

Why is metal malleable?

Answer 88

Positive ions are arranged in regular layers, so if stress is added the layers will be able to move.

Question 89

Why is metal Ductile?

Answer 89

It can be stretched to make wires for electrical usage.

Question 90

Why is metal good conductor of heat?

Answer 90

It has delocalised electrons which are free to move and collide with other particles, passing energy to each other.

Question 91

Why is metal a good conductor of heat?

Answer 91

It has delocalised electrons which carry force. Electrons can move and collide with other particles to carry energy.

Question 92

Why does metal have high melting and high boiling points?

Answer 92

It is strong. There is a strong force of attraction between free electrons and metal ions.

Question 93

What is delocalised mean?

Answer 93

To move freely.