Bonding and structure

Question 1

metallic bonding what are the atoms arranged in?

Answer 1

Crystalline structure where the positive atoms are surrounded by a sea of electrons

Question 2

What holds structure in place in metallic bonding?

Answer 2

Its ELECTROSTATIC ATTRACTION of pos atoms and neg outer electrons that hold structure in place

Question 3

What gives the most metals high mp and bp and what is the rule for this?

Answer 3

The strong electrostatic attraction.

The higher the mp the stronger the electrostatic attraction

Question 4

What happens if one electron (electricity) is inserted into end of a metal and what does this mean for the metal?

Answer 4

An electron is ejected at the other side. It can conduct electricity.

Question 5

Why can metals be bent

Answer 5

As atoms are all same size and in an ordered structure, metals can be bent, know as malleability

Question 6

Covalent bonding

Answer 6

Atoms share pairs of electrons. The covalent bond is a result of 2 pos nuclei being held together by their common attraction for the shared pair of electrons/ the electrostatic attraction between pos nuclei and neg shared electrons

Question 7

Are electrons shared equally in covalent bond?

Answer 7

Yes

Question 8

Why do atoms move together?

Answer 8

The electrons orbit around the nucleus are neg charged and nucleus is pos. the covalent bond is created when neg electrons of one atom are attracted to pos charged nucleus of another atom.

Question 9

Why do atoms eventually stop moving towards each other?

Answer 9

The attraction pulls the atoms together until pos nuclei start to repel each other, it is then balance is reached.

Question 10

What is ionic bonding and what does it create?

Answer 10

Ionic bonds are the electrostatic attraction between pos and neg ions. Ionic compounds form lattice structures of oppositely charged ions

Question 11

What is a London Dispersion Force of attraction between

Answer 11

Between monatomic atoms and small discrete molecules

Question 12

What is the force caused by LDF?

Answer 12

Force is caused by uneven distribution of constantly moving electrons around the nuclei of atoms. The atom has an electron deficient side which is very slightly negative. This is caused by movement of electrons in atoms.

Question 13

Are LDF easily broken and what element and compounds can they be found?

Answer 13

Yes. Elements and compounds with very low melting and boiling points

Question 14

Halogens

Answer 14

Group 7 and they kill bacteria

Question 15

Alkalis

Answer 15

Group 1 and are very reactive

Question 16

alkaline earth metals

Answer 16

group 2

Question 17

Valency of groups and charge

Answer 17

g1: 1 1+
g2: 2 2+
g3: 3 3+
g4: 4 4+or-
g5: -3 -3
g6: -2 -2
g7: -1 -1

Question 18

What accounts for higher melting and boiling points within LDF?

Answer 18

As you go down for instance group 7, the molecules get bigger with more electrons meaning neg dipoles are stronger thus melting and boiling points increase.

Question 19

What does LDF cause the formation of?

Answer 19

Temporary dipoles

Question 20

What are the diatomics

Answer 20

H2
N2
O2
F2
Cl2
Br2
I2

Question 21

What are known as covalent molecular structures?

Answer 21

H, O, N, P, S, halogens, Chlorine nanotubes and fullerenes

Question 22

Give an account of the covalent molecular of nitrogen

Answer 22

Most common gas in air (80%). 2 nitrogen atoms held together by 3 strong covalent binds. N molecules held together by weak LDF.

Question 23

How can LDF increase in strength at lower temps?

Answer 23

LDF increase in strength at lower temps due to decrease in molecular vibration

Question 24

What is not affected in the LDF whether covalent molecules are solid, liquid or gas?

Answer 24

Strong covalent bond holding atoms together is not affected

Question 25

What elements can bond in covalent network structure?

Answer 25

Boron, carbon and silicon

Question 26

Why does graphite conduct

Answer 26

Unlike diamond the carbon atoms in graphite are only bonded three times. This leaves a mobile electron (delocalised electron) to conduct electricity which is found in-between the graphite layers.

Question 27

Why do noble gases not bond/react?

Answer 27

Due to outer electrons having a stable octet, with exception of helium which has filled outer shell of 2 electrons

Question 28

What happens when electricity passed through a noble gas?

Answer 28

When electricity passes through a noble gas they glow and are used in advertising lighting and found inside bulbs and strip lighting.

Question 29

What are intramolecular bonds?

Answer 29

Bonds which join atoms within the molecule

Question 30

What are intermolecular bonds?

Answer 30

Bonds which join individual molecules

Question 31

WHAT ARE PROPERTIES IF COVALENT BONDING (INCLUDING NETWORK) RELATED TO CHANGE OF STATE?

Answer 31

VERY high mp and bp which require intermolecular bonds to be broken for a change of state to occur.

Question 32

What are properties of London Dispersion Forces related to a change of state?

Answer 32

Very low melting and boiling points which require intermolecular bonds to be broken down for a change of state to occur.

Question 33

What have higher melting and boiling points the left hand side or the right hand side of the periodic table?

Answer 33

Higher on the left of the periodic table and fall dramatically for elements on the right as the type of bonding changes.

Question 34

How does reactivity differ in group 1 and why is this?

Answer 34

As you move down group 1 there is an extra shell of electrons being added. This makes the attraction between the outer electron and the positive nucleus weaker, therefor easier to remove the outer electron. Hence more reactive the further you go down.

Question 35

What do the halogens form when they accept electrons?

Answer 35

hallide ions

Question 36

How does reactivity differ with the halogens and why is this?

Answer 36

The halogens reactivity decreases the further they are down the table. This is because the halogen molecule with the more exposed nucleus , has the greater ability to attraction and is therefore more reactive.

Question 37

What is the test for saturated and unsaturated hydrocarbons?

Answer 37

The bromine water test - unsaturated will decolourise the bromine water due to the double bond whereas saturated will not decolourise the bromine water.

Question 38

Q Why does the H+ ion not exist?

Answer 38

H+ has no electrons

Question 39

What is the reaction of the first ionisation energy of sodium?

Answer 39

Na(g) = Na+(g) + e-

Question 40

Why does the first ionisation energy down a group decrease?

Answer 40

The outermost electron being removed is further from the nucleus and increased shielding down the group.

Question 41

How can you decrease the activation energy?

Answer 41

By adding a catalyst