Bonding And Structure

Question 1

Ionic bonding

Answer 1

Occurs in compounds formed from metals combined with non-metals, when metal atoms reacts with non-metal atom electrons in outer shell of metal atom are transferred

Question 2

Metal atoms in ionic bonding

Answer 2

They LOSE electrons to become positively charged ions

Question 3

Non-metal atoms in ionic bonding

Answer 3

They GAIN electrons to become negatively charged ions

Question 4

Ions produced by metals in Groups 1 + 2 + ions produced by non-metals in Groups 6 + 7

Answer 4

They have electronic structure of noble gases (full outer shell, so they’re stable)

Question 5

Ion

Answer 5

Atom or group of atoms that has/have either lost or gained electrons, making it/them either positive (cation) or negative (anion)

Question 6

Ionic compounds

Answer 6

Giant structure of ions, held together by strong electrostatic forces of attraction between oppositely charged ions, forces act in all directions in lattice, has high melting + boiling points as large amount of energy is needed to break many strong bonds, when they’re melted or dissolved in water, they conduct electricity as ions are free to move +, therefore, charge can flow

Question 7

Regular structures (giant ionic lattices)

Answer 7

Have strong electrostatic forces of attraction in all directions between oppositely charged ions

Question 8

Covalent bonding

Answer 8

When atoms share pairs of electrons + it occurs between two or more non-metals, bonds are very strong + they may consist of small molecules

Question 9

Small molecules

Answer 9

Substances that consist of small molecules (usually gases or liquids) have low melting + boiling points, have weak intermolecular forces, when substance melts or boils, these forces are broken, not covalent bonds, DON’T conduct electricity as molecules don’t have overall charge

Question 10

Intermolecular forces

Answer 10

Increase with size of molecules, so larger molecule, higher melting + boiling points

Question 11

Giant covalent structures

Answer 11

Substances that consist of giant covalent structures are solids + have very high melting points, all atoms are linked to other atoms by strong covalent bonds, these bonds must be broken to melt or boil these substances, e.g diamond, graphite, silicon dioxide

Question 12

Diamond

Answer 12

Each carbon atoms forms 4 covalent bonds with other carbon atoms in giant covalent structure, so it’s very hard, it has high melting point + doesn’t conduct electricity as it doesn’t have ions or electrons

Question 13

Graphite

Answer 13

Each carbon atom forms 3 covalent bonds with 3 other carbon atoms, forming layers of hexagonal rings, which have no covalent bonds + can slide as there are weak forces between layers, one electrons from each carbon atom is delocalised, so it can conduct electricity + electrons can move through structure, used in pencils + lubricants as layers can slide over each other, it’s soft + slippery, can be used as electrode as it can conduct electricity

Question 14

Allotrope

Answer 14

Different form of same element as atoms are bonded in different arrangements that create
different giant structures

Question 15

Graphene

Answer 15

Single layer of graphite, so it conducts electricity very well due to delocalised electrons, has properties useful in electronics + composites

Question 16

Fullerene

Answer 16

Molecules of carbon atoms with hollow shapes, structure based on hexagonal rings of carbon atoms, may also contain rings with 5 or 7 carbon atoms, can conduct electricity very well due to delocalised electrons

Question 17

Carbon nanotubes

Answer 17

Cylindrical fullerenes with very high length to diameter ratios, properties make them useful for nanotechnology, electronics + materials, have delocalised electrons, so they can conduct electricity very well

Question 18

Metallic bonding

Answer 18

Metals consist of giant structures of atoms arranged in regular pattern, electrons in outer shell of metal atoms are delocalised + so are free to move through whole structure, sharing of delocalised electrons gives rise to strong metallic bonds, good conductors of electricity as delocalised electrons (‘sea of electrons’) in metal carry electrical charge through metal, good conductors of thermal energy as energy is transferred by delocalised electrons

Question 19

Metals in metallic bonding

Answer 19

Have giant structure of atoms with strong metallic bonding, so most metals have high melting + boiling points

Question 20

Pure metals in metallic bonding

Answer 20

Atoms are arranged in layers, which allows metas to be bent + shaped, but it’s too soft for many uses +, therefore, they’re mixed with other metals to make alloys, which are harder

Question 21

Alloy

Answer 21

Mixture of substances to improve properties, e.g steel, bronze, brass

Question 22

Buckminsterfullerene

Answer 22

60 carbon atoms, has spherical shape + is hollow, so it can be used to carry chemicals inside of it for drugs, can be used as lubricant due to spherical shape