C3- structure and bonding

Question 1

What is an ion?

Answer 1

A particle that is electrically charged.

Question 2

What is a covalent bond?

Answer 2

The attraction between 2 atoms that share 1 or more pairs of electrons.

Question 3

What do you call it when something goes from gas to liquid?

Answer 3

Condensing

Question 4

What do you call it when something goes from liquid to gas?

Answer 4

Evaporation

Question 5

The amount of energy required to change state from solid to liquid, and from liquid to gas depends on what?

Answer 5

The strength of forces between the particles of a substance.

Question 6

The stronger the the force of attraction…?

Answer 6

The more energy required to change state

Question 7

What do you call it when a substance goes from solid to gas?

Answer 7

Sublimination

Question 8

What do you call it when a substance goes from gas to solid?

Answer 8

Deposition

Question 9

Is freezing or melting exo or endothermic

Answer 9

Freezing is exothermic
Melting is endothermic

Question 10

What is the difference between boiling and evaporation?

Answer 10

Evaporation occurs at any temperature and boiling is evaporation at its furthest state where the particles have enough energy to change state.

Question 11

In a heating/cooling curve what goes on the x and y axises?

Answer 11

On the X is time and on the Y is temperature.

Question 12

What is a cation and anion?

Answer 12

A cation is a positive ion and a anion is negative

Question 13

What is meant by the term ‘noble gas configuration’?

Answer 13

When the outer shell is full

Question 14

What is a redox reaction?

Answer 14

When oxidation and reduction happen at the same time ( when one atom transfers an electron to another atom).

Question 15

What is an ionic equation?

Answer 15

When you do a symbol equation but only showing the particles that take place in the reaction.

Question 16

What is a half equation?

Answer 16

When you write an equation for one element in a reaction showing the loss or gain of electrons.

E.g. (Ca)—> (Ca^2+) + (2e-)

Question 17

What does isoelectronic mean?

Answer 17

It means two substances with the same electron configuration.

Question 18

What ions do group 1,2,3,5,6 and 7 form?

Answer 18

Group 1 form 1+ ions
Group 2 form 2+ ions
Group 3 form 3+ ions
Group 5 from 3- ions
Group 6 form 2- ions
Group 7 form 1- ions

Question 19

What is ionic bonding?

Answer 19

Ionic bonding is the strong electrostatic attraction between many oppositely charged ions.

Question 20

Why do ionic compounds have such high boiling and melting points?

Answer 20

As there are so many bonds that need to be broken to separate the ions that it requires a lot of energy.

Question 21

What type of bonding is water?

Answer 21

Covelant

Question 22

What type of bonding is a fluorine molecule?

Answer 22

Covelant

Question 23

What are the physical properties of giant covelant structures?

Answer 23

• have very high melting and boiling points
• are not soluble In water
  -very hard and do not conduct electricity.

Question 24

What is an allotrope?

Answer 24

Different structural forms of the same elements. They can have different physical and structural properties

Question 25

What are some examples of allotropes of carbon?

Answer 25

Diamond, graphite, buckminsterfullerine, graphene

Question 26

How should you structure a question on the why a material is suitable for a curtain job.

Answer 26

1) state structure 2) state bonding 3) properties 4) link back to question

Question 27

Describe the structure of metalic bonding?

Answer 27

The metal cations are positioned in a regular lattice, with the delocalised vailence electrons randomly placed around them which makes the bonding very strong.

Question 28

Why does the metalic bonding diagram show the properties of metal?

Answer 28

-delocalised electrons can freely move throughout the structure (increased conductivity) - when hit the ion layers can slide over each other, as do the delocalised vailence electrons move too preventing the ions from propelling each other.

Question 29

What is an alloy?

Answer 29

An alloy is a mixture of chemical elements where the primary component is a metal.

Question 30

Why do we use alloys instead of pure metals?

Answer 30

-in pure metals, it is easy for the layers to slide over each other, explaining why pure metals are soft. -in an alloy, the atoms are different sizes, distorting the layers making it harder for the layers to slide over each other. The alloy is stronger and harder than pure metal

Question 31

How are ionic compounds held together?

Answer 31

- held together by a giant lattice. - regular structure that extends in all directions in a substance - electrostatic attraction between positive and negative ions holds the structure together

Question 32

Properties of ionic substances?

Answer 32

* Ionic compounds have regular structures (giant ionic lattices) in which there are strong electrostatic forces of attraction in all directions between oppositely charged ions. * They have high melting and boiling points, because a lot of energy is required to break the many strong bonds. * When melted or dissolved in water, ionic compounds conduct electricity because the ions are free to move and carry current. But they can’t conduct electricity when solid because the ions are fixed in place.

Question 33

What are the pros and cons of dot and cross diagrams?

Answer 33

Pros: - easy to visualise transfer of electrons. - show clearly which electrons came from where - show changes of ions Cons: - don’t show structure of the compound - don’t correctly represent size of ions - fails to represent delocalised electrons

Question 34

what are the formula and charges of the following: Hydroxide ion, sulfate ion, nitrate ion, carbonate ion, ammonium ion?

Answer 34

* Hydroxide ion = OH- * Sulfate ion = SO4 2- * Nitrate ion = NO3- * Carbonate ion = CO3 2- * Ammonium ion = NH4+

Question 35

what are the properties of small covelant molecules?

Answer 35

* Substances that consist of small molecules are usually gases or liquids that have low boiling and melting points. * They have weak intermolecular forces between the molecules. These are broken in boiling or melting, not the covalent bonds. -The intermolecular forces increase with the size of the molecules, so larger molecules have higher melting and boiling points. * Substances that consist of small molecules don’t conduct electricity, because small molecules do not have an overall electric charge.

Question 36

describe the properties of diamond and why?

Answer 36

* Diamond is extremely hard and has a very high melting point because each carbon atom forms four strong covalent bonds in a giant covalent structure, requiring a lot of energy to break. * It does not conduct electricity as there are no delocalised electrons.

Question 37

What are the properties of graphite, and why?

Answer 37

* Graphite is soft and slippery because it has layers of carbon atoms held together by weak intermolecular forces, which can easily slide over each other. * It conducts electricity as each carbon forms three bonds, leaving one delocalised electron per atom, which can move and carry charge.

Question 38

What are the properties of graphene, and why?

Answer 38

* Graphene is extremely strong, lightweight, and conducts electricity because it is a single layer of carbon atoms in a hexagonal structure with strong covalent bonds. * It has delocalised electrons, allowing it to conduct electricity efficiently.

Question 39

What are the properties of fullerenes, and why?

Answer 39

* Fullerenes have low melting points due to weak intermolecular forces. * They conduct electricity as they have delocalised electrons. * Carbon nanotubes are strong and lightweight due to their cylindrical covalent structure, making them useful in nanotechnology and electronics.

Question 40

# 1. What are the properties of nanoparticles, and why?

Answer 40

* Nanoparticles are 1-100 nanometers across and contain a few hundred atoms. * They have a very high surface area to volume ratio, meaning they can have different properties compared to bulk materials. * This allows them to be more effective in smaller quantities than larger particles of the same substance.

Question 41

How does the size of nanoparticles affect their surface area to volume ratio, and why is this important?

Answer 41

* As the size of a cube decreases by a factor of 10, the surface area to volume ratio increases by a factor of 10. * This makes nanoparticles highly reactive, making them useful as catalysts and in selective sensors.

Question 42

What are some key applications of nanoparticles, and why?

Answer 42

* Nanoparticles are used in catalysts (due to high surface area), electronics (nanotubes conduct electricity), cosmetics (e.g., sunscreen leaves no white marks), lubricant coatings (reducing friction in artificial joints/gears), and stronger, lightweight materials (e.g., nanotubes in construction).

Question 43

What are potential risks of using nanoparticles?

Answer 43

* Some nanoparticles may be toxic and could enter the bloodstream, potentially reaching the brain and causing harm. * More research is needed to fully understand their long-term health effects.