2025 aqa alevel chemistry paper 3
diamond properties - answers -a macromolecular structure made up of carbon atoms
each bonded to four further carbon atoms
- the strength of the covalent lattice makes rigid
-high melting and boiling point.-covalent bonds in diamond are very strong
-good thermal conductor
ionic bonding (3) - answers - metals and non-metals.
- metal will donate electrons to the non-metal in order to achieve a full outer shell
- allows the molecules to be ionized, forming attraction towards one another due to
opposite charge attraction via electrostatic forces
examples of ionic substances - answers - sodium chloride
-magnesium oxide
What does the group number tell you about what charge the element becomes when it's
an ion? - answers -group 1 = 1+
-group 2 = 2+
-group 3 = 3+
-group 5 = 3-
-group 6 = 2-
-group 7 = - 1-
What are the formulas of the following compound ions?
1. sulfate 2. hydroxide 3. nitrate
4. carbonate 5. ammonium - answers 1. SO₄²⁻ 2. OH⁻ 3. NO₃⁻ 4. CO₃²⁻ 5. NH₄⁺
what are the properties of a giant ionic lattice? - answers -High melting and boiling point
(due to lots of strong bonds between the ions
-brittle,
-when solid, ions are held in place so can't conduct electricity, when they melt the ions
are free to move and carry charge
-when they are dissolved in water the ions separate and are all free to move in the
solution so are free to carry charge
describe ionic bonding - answers -Metals give away the electrons in the outer energy
level so become a positive ion and non-metals gain electrons from the metal so become
a negative ion. They both have a full outer energy level so are more stable (like the
noble gases). Then the electrostatic attraction between the opposite charges bonds
them together.
,How does the ion size affect the electrostatic force of attraction? - answers The smaller
the ions the greater the electrostatic attraction because the ions are closer together.
How does the charge of the ions affect the attraction between ions? - answers The
greater the charge the greater the electrostatic attraction.
Why are ionic compounds brittle - answers They are brittle because when the ions are
forced out of position, like charges line up and cause repulsion and shatter the ionic
compound
What is metallic bonding? - answers A lattice of positive metal ions in a sea of
delocalized electron. The positive metal ions repel each other but this is outweighed by
the electrostatic force of attraction between oppositely charged ions and sea of
delocalized electrons. Forming a giant metallic lattice structure.
Properties of metals - answers conducting at a solid state. (e- can flow easily from -
terminal to +terminal)
- malleable and ductile
- 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
why are giant metallic structures good electrical and thermal conductors? - answers has
a sea of delocalized electrons which are free to move throughout the whole structure
and carry electrical current and thermal energy.
three main factors that affect the strength of metallic bonding - answers 1) charge on
the ion> greater charge = greater number of delocalised electrons + stronger
electrostatic force
2) size of ion> smaller = electrons are closer to positive ions + bond is stronger
Why are metals good conductors of:
1) electricity 2) heat - answers ELECTRICITY :
> bc of the delocalised electrons
> electron from the negative terminal of the supply joins the electron sea at one end of a
metal wire
> at the same time, a different electron leaves the wire at the positive terminal
, HEAT :
> have high thermal conductivities
> bc of sea of electrons
> energy is also spread by increasingly vigorous vibrations ofterm-21 the closely packed
ions
why are metals malleable and ductile - answers - layers of positive ions can easily slide
over one another and take up different positions.
-this doesn't disrupt the metallic bonding as the valence electrons don't belong to any
particular metal atom so they can move with the layers of positive ions, maintaining the
electrostatic forces.
-the metallic bonds are thus not broken and as a result they are strong but flexible so
can be hammered without breaking.
what is covalent bonding? - answers - a covalent bond is a pair of shared electrons
-occurs between non-metals
-electrons are shared so each atom has a stable noble gas arrangement
- maintained due to electrostatic forces shared between pairs of e- and nuclei of bonded
atom (electron cloud)
co-ordinate Bonding - answers The atom that donates electrons has a lone pair. The
atom that accepts the electron pair doesn't have a full outer shell (it is electron deficient)
and can fit a lone pair
How are coordinate bonds shown? - answers Using an arrow pointing from the the atom
donating the electron
what are simple molecular structures - answers when a substance consists of
molecules with intermolecular forces of attraction
-( van der waals, permanent dipoles, hydrogen bonds)
examples of covalent substances - answers -iodine
-ice
-carbon dioxide
-methane
-water
properties of molecular (simple) substances - answers -low bp & mp
-generally poor solubility in water
- poor conductivity (no ions to conduct and electrons)
- mostly gases and liquids
diamond properties - answers -a macromolecular structure made up of carbon atoms
each bonded to four further carbon atoms
- the strength of the covalent lattice makes rigid
-high melting and boiling point.-covalent bonds in diamond are very strong
-good thermal conductor
ionic bonding (3) - answers - metals and non-metals.
- metal will donate electrons to the non-metal in order to achieve a full outer shell
- allows the molecules to be ionized, forming attraction towards one another due to
opposite charge attraction via electrostatic forces
examples of ionic substances - answers - sodium chloride
-magnesium oxide
What does the group number tell you about what charge the element becomes when it's
an ion? - answers -group 1 = 1+
-group 2 = 2+
-group 3 = 3+
-group 5 = 3-
-group 6 = 2-
-group 7 = - 1-
What are the formulas of the following compound ions?
1. sulfate 2. hydroxide 3. nitrate
4. carbonate 5. ammonium - answers 1. SO₄²⁻ 2. OH⁻ 3. NO₃⁻ 4. CO₃²⁻ 5. NH₄⁺
what are the properties of a giant ionic lattice? - answers -High melting and boiling point
(due to lots of strong bonds between the ions
-brittle,
-when solid, ions are held in place so can't conduct electricity, when they melt the ions
are free to move and carry charge
-when they are dissolved in water the ions separate and are all free to move in the
solution so are free to carry charge
describe ionic bonding - answers -Metals give away the electrons in the outer energy
level so become a positive ion and non-metals gain electrons from the metal so become
a negative ion. They both have a full outer energy level so are more stable (like the
noble gases). Then the electrostatic attraction between the opposite charges bonds
them together.
,How does the ion size affect the electrostatic force of attraction? - answers The smaller
the ions the greater the electrostatic attraction because the ions are closer together.
How does the charge of the ions affect the attraction between ions? - answers The
greater the charge the greater the electrostatic attraction.
Why are ionic compounds brittle - answers They are brittle because when the ions are
forced out of position, like charges line up and cause repulsion and shatter the ionic
compound
What is metallic bonding? - answers A lattice of positive metal ions in a sea of
delocalized electron. The positive metal ions repel each other but this is outweighed by
the electrostatic force of attraction between oppositely charged ions and sea of
delocalized electrons. Forming a giant metallic lattice structure.
Properties of metals - answers conducting at a solid state. (e- can flow easily from -
terminal to +terminal)
- malleable and ductile
- 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
why are giant metallic structures good electrical and thermal conductors? - answers has
a sea of delocalized electrons which are free to move throughout the whole structure
and carry electrical current and thermal energy.
three main factors that affect the strength of metallic bonding - answers 1) charge on
the ion> greater charge = greater number of delocalised electrons + stronger
electrostatic force
2) size of ion> smaller = electrons are closer to positive ions + bond is stronger
Why are metals good conductors of:
1) electricity 2) heat - answers ELECTRICITY :
> bc of the delocalised electrons
> electron from the negative terminal of the supply joins the electron sea at one end of a
metal wire
> at the same time, a different electron leaves the wire at the positive terminal
, HEAT :
> have high thermal conductivities
> bc of sea of electrons
> energy is also spread by increasingly vigorous vibrations ofterm-21 the closely packed
ions
why are metals malleable and ductile - answers - layers of positive ions can easily slide
over one another and take up different positions.
-this doesn't disrupt the metallic bonding as the valence electrons don't belong to any
particular metal atom so they can move with the layers of positive ions, maintaining the
electrostatic forces.
-the metallic bonds are thus not broken and as a result they are strong but flexible so
can be hammered without breaking.
what is covalent bonding? - answers - a covalent bond is a pair of shared electrons
-occurs between non-metals
-electrons are shared so each atom has a stable noble gas arrangement
- maintained due to electrostatic forces shared between pairs of e- and nuclei of bonded
atom (electron cloud)
co-ordinate Bonding - answers The atom that donates electrons has a lone pair. The
atom that accepts the electron pair doesn't have a full outer shell (it is electron deficient)
and can fit a lone pair
How are coordinate bonds shown? - answers Using an arrow pointing from the the atom
donating the electron
what are simple molecular structures - answers when a substance consists of
molecules with intermolecular forces of attraction
-( van der waals, permanent dipoles, hydrogen bonds)
examples of covalent substances - answers -iodine
-ice
-carbon dioxide
-methane
-water
properties of molecular (simple) substances - answers -low bp & mp
-generally poor solubility in water
- poor conductivity (no ions to conduct and electrons)
- mostly gases and liquids
