2.2. Bonding and structure - bonds

Question 1

What is the particle theory?

Answer 1

The particle theory describes the movement and arrangement of particles

Question 2

limitations of particle theory

Answer 2

doesn’t consider intermolecular forces, doesn’t consider the difference caused by different particles(atoms, ions, molecules)

Question 3

describe the relationship of charge and electrostatic forces in a structure

Answer 3

greater the charge on the ions, the stronger the electrostatic forces

Question 4

what is a polymer

Answer 4

long chain of monomers

Question 5

what is a monomer

Answer 5

a basic molecule that can chemically bond with identical molecules to form a polymer

Question 6

what is this an example of

Answer 6

polymer

Question 7

melting and boiling point of polymers

Answer 7

Low melting point but higher than simple covalent molecules because the intermolecular forces are stronger because the molecules are bigger.

Question 8

what is an alloy

Answer 8

a mixture of two or more elements, at least one of which is a metal

Question 9

enhanced properties of alloys

Answer 9

stronger, harder, resistance to corrosion or extreme temps

Question 10

why are alloys harder than pure metals

Answer 10

the different sized atoms of the elements distort the layers in the structure, making it more difficult for them to slide over each other

Question 11

why is diamond hard

Answer 11

Each carbon forms four covalent bonds which are strong.

Question 12

what are negative ions called

Answer 12

anions

Question 13

what are positive ions called

Answer 13

cations

Question 14

how to draw a dot and cross diagram

Answer 14

for each ion: write the chemical symbol, draw the outermost electron shell around it, draw brackets to show if it is positive or negative

Question 15

what is an ionic bond

Answer 15

electrostatic force of attraction between two oppositely charged ions

Question 16

giant ionic structure

Answer 16

regular arrangement of alternating positive and negative ions in a lattice. electrostatic forces are incredibly strong- high melting and boiling points

Question 17

what is a covalent bond

Answer 17

the electrostatic attraction between the positively charged nuclei of the atoms and the shared electrons - very strong

Question 18

are covalent bonds strong

Answer 18

yes very strong

Question 19

Do covalent molecules conduct electricity?

Answer 19

No because they have no electrons free to move

Question 20

what is metallic bonding

Answer 20

the electrostatic attraction between positive metal ions and the surrounding delocalised electrons

Question 21

what is the term used for the process when a solid changes directly into a gas

Answer 21

sublimation

Question 22

state symbol for aqueous

Answer 22

aq

Question 23

what is a lattice structure

Answer 23

A regular, repeating pattern of atoms or ions

Question 24

why are ionic compounds good conductors of electricity in the molten state or in solution

Answer 24

ions are able to move and carry a charge

Question 25

Why do simple molecular structures have low melting and boiling points?

Answer 25

there are weak intermolecular forces between the molecules, and so little energy is required to overcome these forces

Question 26

why are simple molecular structures bad conductors

Answer 26

no free ions or electrons to move and carry the charge

Question 27

difference between covalent bonds and intermolecular forces

Answer 27

covalent bonds are found within the molecules between the atoms, while intermolecular forces are found between the molecules

Question 28

Why are giant metallic structures good electrical conductors?

Answer 28

contain delocalised electrons that are free to move through the structure and carry an electrical charge

Question 29

Why are giant metallic structures malleable and ductile?

Answer 29

arranged in layers, layers can slide over each other when force is applied

Question 30

why do giant covalent structures have high melting points

Answer 30

huge number of atoms bonded to other atoms through strong covalent bonds, more energy needed to overcome these bonds

Question 31

how do giant metallic structures conduct heat

Answer 31

delocalised electrons are free to move through the structure and transfer thermal energy

Question 32

in diamond, how many carbon atoms is each carbon atom bonded to

Answer 32

4

Question 33

what are the bonds in diamond

Answer 33

all covalent, no intermolecular forces

Question 34

why can't diamond conduct electricity

Answer 34

no delocalised electrons, all outer shell electrons of the carbon atoms are held in the four covalent bonds

Question 35

why does diamond have a high melting point

Answer 35

There are strong covalent bonds between atoms that are hard to break

Question 36

how many carbon atoms is each carbon atom bonded to in graphite

Answer 36

3

Question 37

why can graphite conduct electricity

Answer 37

Once electron from each carbon atom is delocalised so can carry a charge through the structure

Question 38

why is graphite slippery

Answer 38

layers have weak FORCES between them, so the layers can slide over eachother, allowing graphite to be used in pencils