Bonding

Question 1

What are the 3 types of crystal structures

Answer 1

• giant ionic
• giant covalent
• metallic

Question 2

Explain the structure of ionic bonding ( non- metal and metal )

Answer 2

-Strong electrostatic force of attraction between the oppositely charged ions

• brittle = if we shift the structure we end up with repulsive forces (+ +) so the structure loses its attraction
• When drawing the structure you must make sure the ions are alternating

Question 3

Explain the structure of metallic bonding ( non metals )

Answer 3

• Strong electrostatic force of Attraction between the positive ions and delocalised electrons
• Malleable and ductile ( stretched into thin wires)
  as the layers of ATOMS in metallic bonding are free to slide of each other

Once metals have been reshaped the metal still retains its strength as we still have metallic bonding

Question 4

How many types of covalent bonds are there ( non metals)

Answer 4

single bond = shared pair of electrons (2 electrons)
Double bond = 2 shared pair of electron’s (4 electron’s )
Triple bond = 3 shared pair of electrons ( 6 electrons )

Question 5

What are the mac molecular types of covalent bonding

Answer 5

Diamond
Graphite
Silicon

Question 6

What are the molecular types of covalent bonding

Answer 6

Group 7 atoms but they have a covalent bonds as there are a molecule but BETWEEN the molecules are vandeer walls forces

Question 7

Explain the properties of ionic bonding

Answer 7

High melting point - strong force of attraction between oppositely charged ions so requires large amounts of energy to break these forces

• the more higher the charge the stronger the electrostatic force of attraction

Conduct heat and electricity when molten or dissolved in a solution as the ions are free to move

Question 8

Explain the properties of molecular colvent

Answer 8

Eg. Idoine
Low boiling pint - weak vander waals forces which don’t require a lot of energy to break

they have a covalent bonds as there are a molecule (group 7 are dative atoms ) but BETWEEN the molecules are vandeer walls forces

Question 9

Explain the properties of metalic bonding

Answer 9

High melting point - strong attraction between the positive ions and delocalised electrons so a lot of energy is needed to break the structure

• increased charge on the metal ion = stronger attraction and number of delocalised electrons increase

Conducts electricity and heat - delocalised electrons can carry the charge through the structure

Question 10

describe the structure and bonding in graphite and explain why it has a high melting point

Answer 10

-each carbon is covalently bonded to 3 other carbon atoms to form hexagonal layers. = GIANT COVALENT STRUCTURE
-Between the layers there are weak vander waals forces (layer are free to slide over each other)
-the covalent bonds are strong and require large amounts of energy to break

Question 11

describe the structure and bonding of Diamond
and explain why it has a high melting point

Answer 11

-each carbon is covalently bonded to 4 other carbon atoms allowing a
-giant covalent structure which
-diamond to be very hard as its in a fixed position and
-requires large amounts of energy to break due to strong covalent bonds

Question 12

why can graphite conduct electricity but diamond is not able to

Answer 12

graphite= each carbon delocalises an electrons which is able to carry the charge through the structure
diamond= no delocalised electrons or free moving ions

Question 13

explain why iodine vaporises when heated gently

Answer 13

Vander Waals forces
between the molecules which require little energy to overcome

Question 14

state why iodine is a poor conductor of electricity

Answer 14

no free delocalised electrons

Question 15

explain in terms of its structure and bonding why titanium has a high melting point

Answer 15

titanium has metallic bonding which consists of a strong electrostatic force of attraction between the delocalised electrons and the positive ion causing large amounts of energy needed to break the force

Question 16

why are metals malleable

Answer 16

in metallic bonding the layers of positive ions are free to slide over each other

Question 17

explain why the melting point of aluminium is higher then the melting point of sodium

Answer 17

aluminium forms a 3+ charge while sodium forms a 1+ charge so aluminium has a greater charge = more delocalised electrons= stronger electrostatic force of attraction which requires more energy to break

Question 18

what are the 3 types of intermolecular forces

Answer 18

Vander Waals forces - weakest
dipole-dipole
hydrogen bonding- stongest
* intermolecular forces are much weaker than covalent,ionic, or metallic

Question 19

how are polar bonds made

Answer 19

in a covalent (non-metals) there is a difference in electronegativity between two atoms this allows electrons to be pulled towards the more electronegative atom

Question 20

in a covalent bond, how can it be a non-polar bond

Answer 20

if the bond is between the same two non-metals this allows an equal electronegativity so the electrons are equally attracted to both atoms

Question 21

how are dipole-dipole forces created

Answer 21

in a POLAR BOND there is an electron density switch due to the unequal electronegativity this creates permanent dipoles (s+)(s-)

Question 22

how can some molecules not have a polar bond

Answer 22

if there is more than one covalent bond this allows the polar bond to be arranged symmetrically so the charges cancel out and there are no permanent dipoles anymore

Question 23

how are Vander Waals forces created

Answer 23

electrons are always moving really quickly in the charged cloud this causes a constant electron density switch which creates temporary dipole which are known as van deer waals forces

Question 24

what dose vandeer waals force cause

Answer 24

all atoms and molecules to be attracted to each other as the dipoles are constantly being created and destroyed this allows an overall effect of atoms to be attracted to each other

Question 25

factors that effect the strength of vandeer Waals forces

Answer 25

-size of the molecule
-number of electrons present
*bigger molecule = more electrons
= increase in Vander Waals forces

Question 26

when dose hydrogen bonding happen

Answer 26

when hydrogen is covalently bonded to fluorine, nitrogen, oxygen (most electronegative atoms and the lone pairs on these atoms form a bond with hydrogen) this forms very polarised bonds

Question 27

properties of hydrogen bonding

Answer 27

high boiling and melting point

Question 28

what is electronegativity

Answer 28

The relative tendency of an atoms ability to attract the electron pairs in a covalent bond

Question 29

what dose electronegativity depend on

Answer 29

nuclear charge ,atomic radius, shielding

Question 30

what are the trends in electronegativity

Answer 30

increase in a group as there’s more shielding = more electrons
decrease across a period as there is a greater nuclear charge

Question 31

why are noble gases not electronegative

Answer 31

dont form covalent bonds

Question 32

blurt out the shapes of molecules

Question 33

explain how the strongest type of intermolecular force arises between two molecules of ammonia

Answer 33

a large difference in electronegativity
forms a N (s-) and H (s+)
lone pair on N attracts with H