Bonding

Question 1

Where does ionic bonding occur?

Answer 1

• occurs between a non-metal and metal

Question 2

Why does ionic bonding occur?

Answer 2

• electrons are completely transferred from one atom to another to form ions

Question 3

What is an anion?

Answer 3

Negative ion

Question 4

What is an cation?

Answer 4

Positive ion

Question 5

How many electrons does Group 1 gain or lose?

Answer 5

Loses 1 electron and becomes a +1 positive ion

Question 6

How many electrons does Group 2 gain or lose?

Answer 6

Loses 2 electrons and becomes a +2 positive ion

Question 7

How many electrons does Group 6 gain or lose?

Answer 7

Gain 2 electrons and becomes a negative 2- negative ion

Question 8

How many electrons does Group 7 gain or lose?

Answer 8

Gain 1 electron and becomes a negative 1- negative ion

Question 9

What holds ions together?

Answer 9

Strong electrostatic forces of attraction

Question 10

Can ions conduct electricity?

Answer 10

• when they are aqueous/molten

- ions are free to move and carry a charge

Question 11

Are ions soluble?

Answer 11

Yes

Question 12

Do ions have a low or high melting point?

Answer 12

High

Question 13

Where does covalent bonding occur?

Answer 13

• occurs between 2 non-metals

Question 14

Why does covalent bonding?

Answer 14

When 2 atoms share electrons for a full stable outer shell

Question 15

What is a dative bond?

Answer 15

When 2 electrons are shared but are from the same atom (arrow represents this)

Question 16

What types of covalent structures are there?

Answer 16

• small

- giant

Question 17

What state are small covalent structures at room temperature an why?

Answer 17

• gases as intermolecular forces are weak and don’t need much energy to break

Question 18

Describe the shape of diamond’s structure?

Answer 18

• tetrahedral structure

- 1 bonded to 4 others

Question 19

Why is diamond hard?

Answer 19

• strong covalent bonds between atoms (millions of carbon atoms)

Question 20

Why can’t diamond conduct electricity?

Answer 20

• no free electrons to carry the charge

Question 21

Does diamond and graphite has a high or low melting point?

Answer 21

High

Question 22

Describe the shape of graphite’s structure?

Answer 22

• hexagonal structure

- 1 bonded to 3 others

Question 23

Why is graphite soft?

Answer 23

Weak intermolecular forces between layers which are easily broken so they can slide past each other.

Question 24

How can graphite conduct electricity?

Answer 24

One spare electron on each carbon atom becomes delocalised between the layers and can carry a charge.

Question 25

Why can graphite only conduct electricity in certain directions?

Answer 25

Electrons can't move through layers as they don't have the energy so they conduct parallel to layers not perpendicular.

Question 26

Describe a charged cloud?

Answer 26

An area where you have a big possibility of finding an electron.

Question 27

Why do lone pairs make the shape of a molecules more oval?

Answer 27

They repel each other as they are closer to the central atom and more spread out so they take more space

Question 28

What size should all angles representing charge clouds be?

Answer 28

109.5

Question 29

What are the order of angles in charge clouds

Answer 29

biggest - lone/lone pair second biggest - lone/bonding smallest - bonding/bonding

Question 30

Describe electronegativity?

Answer 30

The ability to attract the bonding pairs in a covalent bond.

Question 31

Explain why electronegativity happens?

Answer 31

- in a covalent bond, two different elements have different electron density that isn't shared equally

Question 32

State the most electronegative elements?

Answer 32

FOClN

Question 33

State the factors affecting electronegativity?

Answer 33

- nuclear charge - atomic radius - shielding

Question 34

Explain the effect of nuclear charge?

Answer 34

- more protons = stronger attraction between nucleus and bonding electrons - high nuclear charge means high electronegativity

Question 35

Explain the effect of atomic radius?

Answer 35

- as radius increases, bonding pairs become further away from nucleus = less attraction to positive nuclear charge - large atomic radius means lower electronegativity

Question 36

Explain the effect of shielding?

Answer 36

- less shells between nucleus and electrons = less repulsion (shielding) = stronger attraction between nucleus and bonding pair of electrons - higher shielding means lower electronegativity

Question 37

Explain the trend down a group?

Answer 37

- atomic radius increases - more shielding - less attraction between nucleus and bonding pair

Question 38

Explain the trends across a period?

Answer 38

- atomic radius - more nuclear charge - stronger attraction between nucleus and bonding a pair

Question 39

Explain what a non-polar bond is?

Answer 39

If electronegativity in both atoms in a covalent are identical, the electrons in the bond will be equally attracted to both of them. THIS RESULTS IN A SYMMETRICAL DISTRIBUTION OF ELECTRON DENSITY! (o2)

Question 40

Explain what a polar bond is?

Answer 40

If electronegativity of both atoms in a covalent bond is different (MORE THAT 0.5) the electrons in the bond will be pulled towards the more electronegative one. THIS RESULTS IN A UNSYMMETRICAL DISTRIBUTION OF ELECTRON DENSITY! (HCl)

Question 41

State what a dipole is?

Answer 41

A difference in a charge between 2 atoms caused by a shift in electron density in the bond.

Question 42

Which type of bonding is more/less polar?

Answer 42

- less polar have more covalent character | - more polar have more ionic character

Question 43

Why is it that even if a molecule has a polar bond it is not necessarily a polar molecules?

Answer 43

There was to be an uneven distribution of charge over the whole molecule - dipole

Question 44

State the three types of intermolecular forces?

Answer 44

1. Instantaneous dipole - dipole forces (Van der Waal) 2. Permanent dipole - dipole force 3. Hydrogen bonds (STRONGEST)

Question 45

Describe a Van der Waal force?

Answer 45

When an instantaneous dipole induces another dipole so opposite charges attract.

Question 46

Describe when a permanent dipole - dipole force happens?

Answer 46

Dipoles are in a manner so the electrostatic attraction between opposite charges align

Question 47

When does hydrogen bond happen?

Answer 47

When hydrogen is bonded to fluorine, nitrogen and oxygen because they are small, polar and have lone pairs.