C3-Structure And Bonding

Question 1

What is covalent bonding

Answer 1

Between 2 non metals
Electrons are shared between the atoms so they have a full outer shell
They are strong and require alot of energy to break

Question 2

Describe a covalent double bond

Answer 2

If an atom needs 2 electrons to complete its outer shell, it shares 2 electrons per atom to make a double bond

Question 3

Why is a covalent bond strong

Answer 3

There is an attraction between the electrons and the positively charged nucleus

Question 4

What is a molecule

Answer 4

A substance which contains two or more covalently bonded atoms

Question 5

What is a lone pair

Answer 5

A pair of electrons thst are not part of the covalent bond

Question 6

What are the properties of a simple covalent compound

Answer 6

Low melting point
Often gases at room temperature

Question 7

What is the difference between the covalent bonds and intermolecular forces in simple covalent compounds

Answer 7

Covalent bonds are very strong
Intermolecular forces are weak

Question 8

What is an ion

Answer 8

An atom with a positive or negative charge due to loss or gain of electrons

Question 9

What is an ionic bond

Answer 9

A bond formed by the electrostatic attraction of oppositely charged ion

Question 10

What is electrostatic

Answer 10

The force between a positive and negative charge

Question 11

How does an ionic bond form

Answer 11

Electrons from outer shell of metal are transferred to the non metal atom
Metal is positive, non metal in negative
There is now an electrostatic force between them which forms an ionic bond

Question 12

Describe an ionic lattice structure

Answer 12

Ionic compound have giant ionic lattices in which there are strong electrostatic forces of attraction in all directions between oppositely charged ions

Question 13

Describe the properties of ionic compounds

Answer 13

High melting points due to strong electrostatic forces between oppositely charged ions-alot of energy is required to break them
Does not conduct electricity as a solid
Do conduct electricity is they are aqueous or liquid as ions are free to move

Question 14

Properties of covalent compounds

Answer 14

Size of intermolecular force gets bigger as the molecules get larger
Do not conduct electricity as they have no free electrons to carry the charge

Question 15

What is a polymer

Answer 15

A very large molecule made from monomers
Large covalent compounds

Question 16

Properties of polymers

Answer 16

Higher melting points than smaller covalent compounds as intermolecular bonds are stronger
Bonds are not as strong as ionic or giant covalent compounds so melting points are lower than those compounds

Question 17

What is metallic bonding

Answer 17

A type of binding that only occurs in metals

Question 18

What is the structure of a metallic bond

Answer 18

Giant structure
Metal atoms form a regular pattern
Donate outer electrons to sea of demoralised electrons

Question 19

What are the properties of metals

Answer 19

Good conductors of electricity due to delocalised electrons that carry charge
Good conductors of heat, free electrons carry energy
Malleable as the layers of ions can easily slid rover one another

Question 20

What is an alloy

Answer 20

Mixture of 2 or more elements, one of which is a metal

Question 21

Describe the structure of an alloy

Answer 21

The regular structure of metal is changed so the layers of ions can no longer slide over one another making it stronger

Question 22

What is the order of the reactivity series

Answer 22

Please- Potassium
Send-Sodium
Lions-Lithium
Cats-Calcium
Monkeys-Magnesium
And-Aluminium
Zebras-Zinc
Into-Iron
Lovely-Lead
Hot-Hydrogen
Countries-Copper
Signed-Silver
General-Gold
Penguin-Platinum

Question 23

What are the 3 giant covalent compounds

Answer 23

Diamond
Graphite
Silica

Question 24

Describe diamond

Answer 24

Each carbon is covalently bonded to 4 other carbons
Very hard
Very high melting point due to strong covalent bonds
Does not conduct electricity-no free electrons

Question 25

Describe graphite

Answer 25

Each carbon is covalently bonded to 3 other carbons There are weak bonds between the layers Hight melting point Conductor of electricity due to delocalised electrons which carry charge Slippery as layers can slide over eachother

Question 26

Describe silica

Answer 26

Every silicon atom is bonded to 3 oxygen atoms and vice versa High melting point

Question 27

What is graphene

Answer 27

A single layer of graphite 1 atom thick

Question 28

What are fullerenes

Answer 28

Molecules of carbon with hollow shapes

Question 29

What are the uses of fullerenes

Answer 29

Drug delivery Catalysts

Question 30

What are carbon nanotubes

Answer 30

Cylinder shapes fullerenes Strong Good conductors of heat/electricity

Question 31

What is a nonoparticle

Answer 31

A particle between 1nm and 100nm in diameter Extremely large surface area

Question 32

Catalyst

Answer 32

A substance which speeds up a reaction, by providing an alternate pathway, without being used up

Question 33

What are the potential applications of nanoparticles in medicine

Answer 33

Targeted delivery of drugs-more easily absorbed, could be used to deliver drugs to specific tissues Making synthetic skin

Question 34

What are the other uses of nanoparticles

Answer 34

Silver nanoparticles have antibacterial properties Some nanoparticles are electrical conductors Can be used in cosmetics to make them less oily Used in sun creams-provide better UV protection than conventional sun creams

Question 35

What are the dangers of nanomaterials

Answer 35

Long term affects on the body have not been well researched When used in suncream nanoparticles are absorbed through the skin

Question 36

what does a dot and cross diagram show

Answer 36

How electrons are transferred It does not show the 3D of an ionic compound or that it is a giant compound

Question 37

What does the 2D ball and stick model of ionic bonding show

Answer 37

The electrostatic forces that happen between oppositely charged ions in an ionic compound But it does not show the 3D structure of an ionic compound

Question 38

What does the 3D ball and stick model of ionic bonding show

Answer 38

The 3D structure of the ionic lattice and how different ions interact with other ions in all directions to create an ionic lattice

Question 39

Describe the particles in a solid

Answer 39

They vibrate around a fixed position Strong force of attraction between each particle Very close together

Question 40

Describe the particles in a liquid

Answer 40

Close together but can move in any direction Wont keep a fixed shape like solids do

Question 41

Describe the particles in a gas

Answer 41

Particles are very far apart Move randomly in all directions Often collide with each other