AQA A LEVEL CHEMISTRY PAPER 1 AND PAPER
2 7405 CERTIFICATION
ANSWERS
◉ Define ionic bond. Answer: electrostatic attraction that binds
oppositely charged ions together
◉ Ionic Lattice. Answer: - structure of an ionic compound.
- Allows compound to be brittle and non-conductive in a solid state
- giant
◉ Properties of ionic compounds. Answer: Giant ionic structures
High melting points (giant)
Solid at room temp
Conduct electricity when molten or dissolved (e- free to move)
Brittle (due to alternating + and - ions, a slight change may cause
contact between like ions)
◉ Covalent Bonding. Answer: - bond between non-metals.
- non-metals will share an electron each to form a single bond (or 2
for double and 3 for triple bonds).
,- maintained due to electrostatic forces shared between pairs of e-
and nuclei of bonded atom (electron cloud)
◉ Define electron cloud. Answer: electrons move within area around
nucleus
◉ double covalent bond
E.G SO2. Answer: - 4e- shared (E.G. ethene, O2 and CO2)
1. S needs 2e- and O needs 2e- each
2. Draw O first, both with 2e- from Sulfur
3. Sulfur will only need 2e so draw it from one O as only in pairs
◉ Co-ordinate Bonding. Answer: - bond by which a lone pair of
electrons shares its pair with an atom that is electron deficient.
- type of covalent bond, also known as dative covalent bonding
- arrow points towards accepting atom
- One atom provides both e-
E.G Ammonium ion NH4+
◉ Electron deficient. Answer: referring to a bonded atom, such as Be
or B, that has fewer than eight valence electrons
, ◉ Define valence. Answer: Unpaired electrons in the outer shell that
tell you how many bonds can form
◉ properties of covalent compounds. Answer: - Low melting point
(bonds are only between the atoms within the molecule, weak
attraction between molecules)
- Poor conductors of electricity (molecules are neutral overall)
◉ Metallic Bonding. Answer: - bond between metals.
- Consists of positive ions dispersed in a sea of delocalised electrons.
- e- depends on how many e- from each metal atom
- Giant
◉ Properties of metals. Answer: - conducting at a solid state. (e- can
flow easily from -terminal to +terminal)
- sea also allows the metal to be malleable and ductile (as when
slightly bent, it is still in the same environment)
- strength:
Charge on ion (greater the charge, more e- so greater electrostatic
attraction)
Size of ion (smaller the ion, closer the e- to +nucleus, stronger the
bond)
- giant structures so high MP/BP. Strong electrostatic attraction
2 7405 CERTIFICATION
ANSWERS
◉ Define ionic bond. Answer: electrostatic attraction that binds
oppositely charged ions together
◉ Ionic Lattice. Answer: - structure of an ionic compound.
- Allows compound to be brittle and non-conductive in a solid state
- giant
◉ Properties of ionic compounds. Answer: Giant ionic structures
High melting points (giant)
Solid at room temp
Conduct electricity when molten or dissolved (e- free to move)
Brittle (due to alternating + and - ions, a slight change may cause
contact between like ions)
◉ Covalent Bonding. Answer: - bond between non-metals.
- non-metals will share an electron each to form a single bond (or 2
for double and 3 for triple bonds).
,- maintained due to electrostatic forces shared between pairs of e-
and nuclei of bonded atom (electron cloud)
◉ Define electron cloud. Answer: electrons move within area around
nucleus
◉ double covalent bond
E.G SO2. Answer: - 4e- shared (E.G. ethene, O2 and CO2)
1. S needs 2e- and O needs 2e- each
2. Draw O first, both with 2e- from Sulfur
3. Sulfur will only need 2e so draw it from one O as only in pairs
◉ Co-ordinate Bonding. Answer: - bond by which a lone pair of
electrons shares its pair with an atom that is electron deficient.
- type of covalent bond, also known as dative covalent bonding
- arrow points towards accepting atom
- One atom provides both e-
E.G Ammonium ion NH4+
◉ Electron deficient. Answer: referring to a bonded atom, such as Be
or B, that has fewer than eight valence electrons
, ◉ Define valence. Answer: Unpaired electrons in the outer shell that
tell you how many bonds can form
◉ properties of covalent compounds. Answer: - Low melting point
(bonds are only between the atoms within the molecule, weak
attraction between molecules)
- Poor conductors of electricity (molecules are neutral overall)
◉ Metallic Bonding. Answer: - bond between metals.
- Consists of positive ions dispersed in a sea of delocalised electrons.
- e- depends on how many e- from each metal atom
- Giant
◉ Properties of metals. Answer: - conducting at a solid state. (e- can
flow easily from -terminal to +terminal)
- sea also allows the metal to be malleable and ductile (as when
slightly bent, it is still in the same environment)
- strength:
Charge on ion (greater the charge, more e- so greater electrostatic
attraction)
Size of ion (smaller the ion, closer the e- to +nucleus, stronger the
bond)
- giant structures so high MP/BP. Strong electrostatic attraction
