C3 - structure and bonding

Question 1

What are the three states of matter and their symbols?

Answer 1

States of matter: solid (s), liquid (l), gas (g).

Question 2

What is melting?

Answer 2

The process where a solid turns into a liquid when heated.

Question 3

What is freezing?

Answer 3

The process where a liquid turns into a solid when cooled.

Question 4

What is boiling?

Answer 4

The process where a liquid turns into a gas when heated.

Question 5

What is condensing?

Answer 5

The process where a gas turns into a liquid when cooled.

Question 6

How are particles arranged in solids?

Answer 6

Closely packed in a fixed, regular arrangement.

Question 7

How are particles arranged in liquids?

Answer 7

Closely packed but can move past each other.

Question 8

How are particles arranged in gases?

Answer 8

Far apart and move freely.

Question 9

Which particles are involved in ionic bonding?

Answer 9

Positively charged metal ions and negatively charged non-metal ions.

Question 10

How does a Group 1 metal atom become a positive ion?

Answer 10

It loses one electron to form a +1 ion.

Question 11

How does a Group 7 non-metal atom become a negative ion?

Answer 11

It gains one electron to form a −1 ion.

Question 12

What causes opposite charges to attract?

Answer 12

Electrostatic forces between positive and negative charges.

Question 13

What are the charges of ions in Group 1, Group 2, Group 6, and Group 7?

Answer 13

Group 1: +1, Group 2: +2, Group 6: −2, Group 7: −1.

Question 14

How can you determine the state of a substance at a given temperature?

Answer 14

By comparing the temperature to the substance’s melting and boiling points.

Question 15

How does energy, movement, and attraction between particles change when heated?

Answer 15

Energy and movement increase; attraction decreases as particles move apart.

Question 16

What happens at the melting and boiling points in terms of particles?

Answer 16

Energy breaks bonds between particles; temperature remains constant during the phase change.

Question 17

What factors affect the rate of evaporation?

Answer 17

Surface area, temperature, and air movement.

Question 18

Why do substances have different melting and boiling points?

Answer 18

Due to differences in the strength of forces between particles.

Question 19

What are the limitations of the particle model?

Answer 19

It doesn’t show forces between particles or energy changes accurately.

Question 20

How do you draw dot and cross diagrams for compounds formed between Group 1 and Group 7 elements?

Answer 20

Show electrons from metal lost and non-metal gained, with correct charges.

Question 21

How does electron transfer allow ionic bonding between Group 1 and Group 7 elements?

Answer 21

Metal loses an electron; non-metal gains an electron; opposite charges attract.

Question 22

How can you draw dot and cross diagrams for unfamiliar ionic compounds?

Answer 22

Determine charges and transfer electrons accordingly.

Question 23

How does an element’s position on the periodic table relate to its stable ion charge?

Answer 23

Group number indicates charge for main group elements.

Question 24

How do unfamiliar elements become ions based on electronic structure?

Answer 24

They lose or gain electrons to achieve a full outer shell.

Question 25

How can you predict the charge of a monatomic ion using periodic table position?

Answer 25

Group number correlates with ion charge.

Question 26

How do you suggest charges on unfamiliar ions?

Answer 26

By examining their group number and electronic configuration.

Question 27

How do you explain the ratio of metal and non-metal ions in compounds?

Answer 27

Ions combine in ratios that balance total positive and negative charges.

Question 28

What is an ionic lattice?

Answer 28

A giant structure of ions arranged in a repeating pattern.

Question 29

How do you interpret the formula of ionic compounds?

Answer 29

It shows the ratio of ions present.

Question 30

Why do ionic compounds have high melting points?

Answer 30

Strong electrostatic forces between ions require lots of energy to break.

Question 31

How do you generate formulas of ionic compounds given ion charges?

Answer 31

Balance total positive and negative charges to zero.

Question 32

Why can ionic compounds conduct electricity only when molten or dissolved?

Answer 32

Ions are free to move and carry charge.

Question 33

What state allows ionic compounds to conduct electricity?

Answer 33

Molten or dissolved in water.

Question 34

How do ions move to conduct electricity?

Answer 34

Ions flow toward electrodes carrying charge.

Question 35

How do you justify that a compound has ionic bonding?

Answer 35

By its physical properties like high melting point and conductivity when molten.

Question 36

What is a covalent bond?

Answer 36

A shared pair of electrons between atoms.

Question 37

How does a covalent bond form in terms of electronic structure?

Answer 37

Atoms share electrons to fill outer shells.

Question 38

How can ionic models predict physical properties of ionic compounds?

Answer 38

Strong ionic bonds explain high melting points and brittleness.

Question 39

How do you draw dot and cross and ball and stick diagrams for small molecules?

Answer 39

Show shared electron pairs and atom positions.

Question 40

How can you recognize covalent compounds from formulas or diagrams?

Answer 40

They show shared electrons and typically non-metal atoms.

Question 41

What are examples of small molecules with covalent bonds?

Answer 41

H2, Cl2, O2, N2, HCl, H2O, NH3, CH4.

Question 42

What is a double bond in diatomic molecules?

Answer 42

Two pairs of shared electrons between atoms.

Question 43

Why do small molecules have low melting and boiling points?

Answer 43

Weak intermolecular forces require little energy to overcome.

Question 44

How does molecule size affect melting and boiling points?

Answer 44

Larger molecules have stronger intermolecular forces.

Question 45

How might double bonds affect properties compared to single bonds?

Answer 45

Double bonds are stronger and shorter, affecting reactivity and boiling points.

Question 46

How do you predict physical properties of unfamiliar covalent substances?

Answer 46

Based on size, bonding type, and intermolecular forces.

Question 47

Why don’t small molecules conduct electricity?

Answer 47

They have no free ions or electrons.

Question 48

Why don’t small molecules and polymers conduct electricity?

Answer 48

No charged particles free to move.

Question 49

How do properties differ between substances with different bonding?

Answer 49

Ionic: high melting, conducts electricity when molten; covalent: low melting, no conductivity.

Question 50

What is an intermolecular force?

Answer 50

Attractive forces between molecules.

Question 51

Which substances have weak intermolecular forces?

Answer 51

Small non-polar molecules.

Question 52

How do models explain physical properties of small molecules?

Answer 52

By showing particle arrangement and bonding, though limited.

Question 53

What are the melting points and solubility of ionic compounds?

Answer 53

High melting points and soluble in water.

Question 54

Describe giant ionic structures.

Answer 54

3D networks of ions held by ionic bonds.

Question 55

What is metallic bonding?

Answer 55

Delocalized electrons holding metal ions together.

Question 56

How can models of graphene, nanotubes, and fullerenes explain properties?

Answer 56

Show structure affects strength, conductivity, and uses.

Question 57

How do metals form giant structures?

Answer 57

Atoms packed closely with delocalized electrons.

Question 58

How can metallic bonding be diagrammatically represented?

Answer 58

Positive ions in a sea of delocalized electrons.

Question 59

What physical properties do metals have?

Answer 59

High melting points, conductivity, malleability.

Question 60

How does metallic bonding explain metals’ properties?

Answer 60

Delocalized electrons allow conductivity and malleability.

Question 61

How do alloys affect metal structure and properties?

Answer 61

Alloy atoms distort lattice, making metals harder.

Question 62

Why are metals alloyed?

Answer 62

To improve strength and resistance to corrosion.

Question 63

Why are alloys used more often than pure metals?

Answer 63

Because they have better properties for most uses.

Question 64

What is nanoscience?

Answer 64

The study of materials sized between 1 and 100 nanometers.

Question 65

How big are nanoparticles?

Answer 65

Between 1 and 100 nanometers.

Question 66

How do you classify particles by size?

Answer 66

Coarse (>2500 nm), fine (100-2500 nm), nanoparticles (1-100 nm).

Question 67

How does surface area to volume ratio change with particle size?

Answer 67

Surface area to volume ratio increases as particle size decreases.

Question 68

Why does surface area to volume ratio increase as particles get smaller?

Answer 68

Because surface area decreases less rapidly than volume.

Question 69

What are negative indices in nanoscience standard form?

Answer 69

Very small numbers using powers of ten with negative exponents.

Question 70

What are some uses of nanoparticles?

Answer 70

Sun cream, catalysts, medicine.

Question 71

How do you convert lengths into standard form?

Answer 71

Express numbers as a × 10ⁿ.

Question 72

How does surface area to volume ratio affect properties?

Answer 72

Higher ratios increase reactivity and affect melting points.

Question 73

How do you convert standard form into various units?

Answer 73

Multiply or divide by powers of ten for unit conversion.

Question 74

What are advantages and disadvantages of nanoparticles?

Answer 74

Advantages: increased reactivity, new properties; Disadvantages: unknown health/environmental effects.

Question 75

How do you evaluate nanoparticle applications?

Answer 75

Balance benefits in medicine and industry against safety concerns.

Question 76

Why do nanoparticles have new applications?

Answer 76

Unique properties due to small size and high surface area.

Question 77

Why should nanotechnology research continue?

Answer 77

To harness benefits while understanding risks.

Question 78

Why do alloys tend to be harder than pure metals?

Answer 78

Alloy atoms distort the metal lattice, preventing easy layer movement.

Question 79

How does increasing temperature affect evaporation rate?

Answer 79

Higher temperature increases particle energy and evaporation rate.

Question 80

Why can ionic compounds conduct electricity when molten/dissolved but not solid?

Answer 80

Ions are free to move only when molten or dissolved.

Question 81

What are limitations of the particle model in explaining changes of state?

Answer 81

Does not show forces or energy changes accurately.

Question 82

How does high surface area to volume ratio affect nanoparticles?

Answer 82

Increases reactivity and changes physical properties.

Question 83

Why do covalent molecules generally have low melting and boiling points?

Answer 83

Weak intermolecular forces compared to covalent bonds.

Question 84

How does molecule size affect boiling points?

Answer 84

Larger molecules have stronger intermolecular forces and higher boiling points.

Question 85

What makes graphene useful?

Answer 85

Strong, flexible, and good electrical conductor due to its carbon atom layer structure.