AQA Chemistry A level
1. What is the relative mass and charge on a proton?: Mass 1 charge +1
2. What is the relative mass and charge on a neutron?: Mass 1 Charge 0
3. What is the relative mass and charge on an electron?: Mass 1/2000
Charge -1
4. What is the mass number?: The total number of protons and neutrons in
the nucleus of an atom
5. What is the Atomic (proton) number?: This is the number of protons in the
nucleus of an atom and is used to identify an element
6. What are Ions?: Ion have different numbers of protons and electrons.
Negative ions have more electrons than protons and positive ions have fewer
electrons than protons.
7. What are isotopes?: Isotopes of an element are atoms with the same
number of protons but different numbers of neutrons
8. describe Thomson's model of the atom.: Thomson's model of the atom
was like a 'plum pudding' with a positively charged pudding (solid sphere) that
contained negatively charged particles (electrons).
9. What was found in Rutherford's gold foil experiment?: When alpha
particles were fired at a thin gold sheet, most of them passed straight through with
a very small number deflected straight back.
10. What was Rutherford's new nuclear model for the atom?: A tiny
positively charged nucleus at the centre, surrounded by a cloud of negative
electrons. Most of the atom is empty space.
11. What did Bohr's atom model show?: Electrons only exist in fixed orbits
and not anywhere in between. Each Shell has a fixed energy.
When an electron moves between shells, electromagnetic radiation is emitted or
absorbed.
Because the energy of the shells is fixed, the radiation will have a fixed energy.
12. What difference is found between the original Bohr atom model and the
refined Bohr model?: Scientists discovered that not all electrons in a shell have
the same energy, so it was refined to include sub shell's.
13. What is relative atomic mass?: The average mass of an atom of an
element compared to one twelfth of the mass of an atom of carbon 12.
14. What is relative isotopic mass?: Relative isotopic mass is the mass of an
atom of an isotope of an element on a scale where an atom of Carbon-12 is
exactly 12.
15. Calculating relative atomic mass: relative atomic mass = isotopic masses
x percentages/total percentage
, .
16 What is relative molecular mass?: The average mass of an entity compared
to one twelfth of the mass of an atom of carbon 12.
17. What is the equation used to calculate the number of moles of any
substance?: Number of moles = mass(g)/ mass of one mole (mol)
18. What are the 5 stages in mass spectrometery?: vaporisation, ionisation,
acceleration, deflection, and detection
19. What happens during the vaporisation stage of mass spectrometry?: The
sample is turned into a gas using an electrical heater in a vacuum.
20. What happens during the ionisation stage of mass spectrometry?: An
electron gun fires a beam of high energy electrons which bombards the
gaseous particles, knocking off electrons leaving a positive ion
21. What happens during the acceleration stage of mass spectrometry?: The
positive ions are attracted by negatively charged plates in an electric field
which accelerates the ions and focuses the beam.
22. What happens during the deflection stage of mass spectrometry?: The
fast moving ions pas into a string magnetic field, deflecting the ions into a
curved path. The degree of deflection depends on the Mass/charge ratio (m/z).
Ions with with a high m/z ratio are deflected the least (they're heavier). The
strength of the magnet is gradually increased so that ions with different m/z
ratios are deflected towards the detector.
23. What happens during the detection stage of mass spectrometry?: The
positive ions hit an electrically charged plate/ the current produced is then
amplified and recorded as a 'peak'. Each peak is a measure of the relative
abundance of each ion.
24. What is the general ionisation equation?: X(g) => X+ = e-
25. What does a mass spectrum chart show?: Each line represents a different
isotope of an element. the height of each peak gives the relative isotopic
abundance (the amount of it). For a molecular substance the peak with the
greatest m/z ratio corresponds to the Mr.
26. What are the steps in calculating relative atomic mass?: Step 1: For each
peak multiply the relative isotopic abundance by the relative isotopic mass.
Step 2: Add up these totals.
Step 3: Divide by 100
27. How many orbitals do each-sub shell contain?: s - 1 p - 3 d - 5 f - 7
28. What are four rules for electronic arrangement notation?: 1: Each
principle and subsidiary level fills up before the next one
2: When the 3p energy level is full, the 4s level fills before the 3d
3: When an atom or ion has 3d electrons, the 4s is written after the 3d
, AQA Chemistry A level
4: Atoms that have 3d electrons always lose the 4s electrons first while forming ions
29. What is the first ionisation energy?: The first ionisation energy is the energy
needed to remove 1 electron from each atom in 1 mole of gaseous atoms to form 1
mole of gaseous atoms to form 1 mole of gaseous 1+ ions.
30. How does nuclear charge affect ioniation energy?: The more protons that
are in the nucleus, the more positively charged the nucleus is and the stronger
the attraction for the electrons
31. How does distance from the nucleus affect ionisation energy?: Attraction
falls off very rapidly with distance. An electron close to the nucleus will be
much more strongly attracted than one further away.
32. How does shielding affect ionisation energy?: As the number of electrons
between the outer electrons and the nucleus increases, the outer electrons
feel less attraction towards the nuclear charge. This lessening pull of the
nucleus by inner shells of electrons is called shielding.
33. What is the second ionisation energy?: The second ionisation energy is the
energy needed to remove an electron from each ion in 1 mole of gaseous 1+
ions.
34. What is the trend in ionisation energy down group 2?: First ionisation
energy decreases down Group 2. This provided evidence that electron shells
really do exist.
35. What is the trend in ionisation energy across periods?: As you move
across a period the general trend is for the ionisation energy to increase, it
gets harder to remove an electron. This is because the number of protons is
increasing which means a stronger nuclear attraction.
There are small drops between groups 2 and 3 due to sub-shell structure, the
electron is in a new sub-shell so further away from nucleus, more electron shielding
There is a drop between groups 5 and 6 due to electron repulsion. the repulsion
between two electrons in an orbital means that the electrons are easier to remove
from shared orbitals.
36. What is molar mass?: The mass of one mole of something, the same as
relative molecular mass but the units are g mol-1
37. What is the equation linking the number of moles to concentration and
volume?: number of moles = concentration x volume (in dm3)
38. What is the ideal gas equation?: pV=nRT
p = pressure in pascals V
= Volume in m3 n =
, .
number of moles R =
8.31 the gas constant
T = temperature measured in kelvin
39 What is a neutralisation reaction?: When an acid reacts with an alkali and a
salt and water is produced.
40. What is an empirical formula?: The empirical formula gives the smallest
whole number ratio of atoms in a compound.
41. What is the molecular formula?: The molecular formula gives the actual
numbers of atoms in a molecule.
42. What is the theoretical yield?: The theoretical yield is the mass of the product
that should be formed in a chemical reaction. It assumes no chemicals are 'lost' in
the process.
43. What is percentage yield and what is its formula?: For any reaction the
actual mass of the product (actual yield) will be less than the theoretical yield.
percentage yield = actual yield / theoretical yield x 100
44. What is Atom economy?: Atom economy is a measure of the proportion of
reactant atoms that become part of the desired product (rather than by-products) in
the balanced chemical equation.
45. What is the formula for Atom economy?: % atom economy = mass of
desired product / total mass of reactants x 100
46. What is electrostatic attraction?: Electrostatic attraction holds positive and
negative ions together - it is very strong.
47. What is ionic bonding?: Ionic bonding is bonds that have electrostatic
attraction. When oppositely charged ions form an ionic bond you get an ionic
compound.
48. What are giant ionic lattices?: A lattice is just a regular structure. Ionic
crystals are giant lattices of ions. Different ionic compounds have different shaped
structures but they're all still giant lattices.
49. What is the electrical conductivity of an ionic compound?: Ionic
compounds conduct electricity when they're molten or dissolved - but not when
they're solid. The ions in a liquid are free to move and carry a charge. In a solid
they're in a fixed position by the strong ionic bonds.
50. What is the melting point for ionic compounds?: Ionic compounds have
high melting points. The giant ionic lattices are held together by strong electrostatic
forces. It takes lots of energy to overcome these forces, so melting points are very
high.
51. What is the solubility of ionic compounds?: Ionic compounds tend to
dissolve in water. Water molecules are polar - part of the molecule has a small
1. What is the relative mass and charge on a proton?: Mass 1 charge +1
2. What is the relative mass and charge on a neutron?: Mass 1 Charge 0
3. What is the relative mass and charge on an electron?: Mass 1/2000
Charge -1
4. What is the mass number?: The total number of protons and neutrons in
the nucleus of an atom
5. What is the Atomic (proton) number?: This is the number of protons in the
nucleus of an atom and is used to identify an element
6. What are Ions?: Ion have different numbers of protons and electrons.
Negative ions have more electrons than protons and positive ions have fewer
electrons than protons.
7. What are isotopes?: Isotopes of an element are atoms with the same
number of protons but different numbers of neutrons
8. describe Thomson's model of the atom.: Thomson's model of the atom
was like a 'plum pudding' with a positively charged pudding (solid sphere) that
contained negatively charged particles (electrons).
9. What was found in Rutherford's gold foil experiment?: When alpha
particles were fired at a thin gold sheet, most of them passed straight through with
a very small number deflected straight back.
10. What was Rutherford's new nuclear model for the atom?: A tiny
positively charged nucleus at the centre, surrounded by a cloud of negative
electrons. Most of the atom is empty space.
11. What did Bohr's atom model show?: Electrons only exist in fixed orbits
and not anywhere in between. Each Shell has a fixed energy.
When an electron moves between shells, electromagnetic radiation is emitted or
absorbed.
Because the energy of the shells is fixed, the radiation will have a fixed energy.
12. What difference is found between the original Bohr atom model and the
refined Bohr model?: Scientists discovered that not all electrons in a shell have
the same energy, so it was refined to include sub shell's.
13. What is relative atomic mass?: The average mass of an atom of an
element compared to one twelfth of the mass of an atom of carbon 12.
14. What is relative isotopic mass?: Relative isotopic mass is the mass of an
atom of an isotope of an element on a scale where an atom of Carbon-12 is
exactly 12.
15. Calculating relative atomic mass: relative atomic mass = isotopic masses
x percentages/total percentage
, .
16 What is relative molecular mass?: The average mass of an entity compared
to one twelfth of the mass of an atom of carbon 12.
17. What is the equation used to calculate the number of moles of any
substance?: Number of moles = mass(g)/ mass of one mole (mol)
18. What are the 5 stages in mass spectrometery?: vaporisation, ionisation,
acceleration, deflection, and detection
19. What happens during the vaporisation stage of mass spectrometry?: The
sample is turned into a gas using an electrical heater in a vacuum.
20. What happens during the ionisation stage of mass spectrometry?: An
electron gun fires a beam of high energy electrons which bombards the
gaseous particles, knocking off electrons leaving a positive ion
21. What happens during the acceleration stage of mass spectrometry?: The
positive ions are attracted by negatively charged plates in an electric field
which accelerates the ions and focuses the beam.
22. What happens during the deflection stage of mass spectrometry?: The
fast moving ions pas into a string magnetic field, deflecting the ions into a
curved path. The degree of deflection depends on the Mass/charge ratio (m/z).
Ions with with a high m/z ratio are deflected the least (they're heavier). The
strength of the magnet is gradually increased so that ions with different m/z
ratios are deflected towards the detector.
23. What happens during the detection stage of mass spectrometry?: The
positive ions hit an electrically charged plate/ the current produced is then
amplified and recorded as a 'peak'. Each peak is a measure of the relative
abundance of each ion.
24. What is the general ionisation equation?: X(g) => X+ = e-
25. What does a mass spectrum chart show?: Each line represents a different
isotope of an element. the height of each peak gives the relative isotopic
abundance (the amount of it). For a molecular substance the peak with the
greatest m/z ratio corresponds to the Mr.
26. What are the steps in calculating relative atomic mass?: Step 1: For each
peak multiply the relative isotopic abundance by the relative isotopic mass.
Step 2: Add up these totals.
Step 3: Divide by 100
27. How many orbitals do each-sub shell contain?: s - 1 p - 3 d - 5 f - 7
28. What are four rules for electronic arrangement notation?: 1: Each
principle and subsidiary level fills up before the next one
2: When the 3p energy level is full, the 4s level fills before the 3d
3: When an atom or ion has 3d electrons, the 4s is written after the 3d
, AQA Chemistry A level
4: Atoms that have 3d electrons always lose the 4s electrons first while forming ions
29. What is the first ionisation energy?: The first ionisation energy is the energy
needed to remove 1 electron from each atom in 1 mole of gaseous atoms to form 1
mole of gaseous atoms to form 1 mole of gaseous 1+ ions.
30. How does nuclear charge affect ioniation energy?: The more protons that
are in the nucleus, the more positively charged the nucleus is and the stronger
the attraction for the electrons
31. How does distance from the nucleus affect ionisation energy?: Attraction
falls off very rapidly with distance. An electron close to the nucleus will be
much more strongly attracted than one further away.
32. How does shielding affect ionisation energy?: As the number of electrons
between the outer electrons and the nucleus increases, the outer electrons
feel less attraction towards the nuclear charge. This lessening pull of the
nucleus by inner shells of electrons is called shielding.
33. What is the second ionisation energy?: The second ionisation energy is the
energy needed to remove an electron from each ion in 1 mole of gaseous 1+
ions.
34. What is the trend in ionisation energy down group 2?: First ionisation
energy decreases down Group 2. This provided evidence that electron shells
really do exist.
35. What is the trend in ionisation energy across periods?: As you move
across a period the general trend is for the ionisation energy to increase, it
gets harder to remove an electron. This is because the number of protons is
increasing which means a stronger nuclear attraction.
There are small drops between groups 2 and 3 due to sub-shell structure, the
electron is in a new sub-shell so further away from nucleus, more electron shielding
There is a drop between groups 5 and 6 due to electron repulsion. the repulsion
between two electrons in an orbital means that the electrons are easier to remove
from shared orbitals.
36. What is molar mass?: The mass of one mole of something, the same as
relative molecular mass but the units are g mol-1
37. What is the equation linking the number of moles to concentration and
volume?: number of moles = concentration x volume (in dm3)
38. What is the ideal gas equation?: pV=nRT
p = pressure in pascals V
= Volume in m3 n =
, .
number of moles R =
8.31 the gas constant
T = temperature measured in kelvin
39 What is a neutralisation reaction?: When an acid reacts with an alkali and a
salt and water is produced.
40. What is an empirical formula?: The empirical formula gives the smallest
whole number ratio of atoms in a compound.
41. What is the molecular formula?: The molecular formula gives the actual
numbers of atoms in a molecule.
42. What is the theoretical yield?: The theoretical yield is the mass of the product
that should be formed in a chemical reaction. It assumes no chemicals are 'lost' in
the process.
43. What is percentage yield and what is its formula?: For any reaction the
actual mass of the product (actual yield) will be less than the theoretical yield.
percentage yield = actual yield / theoretical yield x 100
44. What is Atom economy?: Atom economy is a measure of the proportion of
reactant atoms that become part of the desired product (rather than by-products) in
the balanced chemical equation.
45. What is the formula for Atom economy?: % atom economy = mass of
desired product / total mass of reactants x 100
46. What is electrostatic attraction?: Electrostatic attraction holds positive and
negative ions together - it is very strong.
47. What is ionic bonding?: Ionic bonding is bonds that have electrostatic
attraction. When oppositely charged ions form an ionic bond you get an ionic
compound.
48. What are giant ionic lattices?: A lattice is just a regular structure. Ionic
crystals are giant lattices of ions. Different ionic compounds have different shaped
structures but they're all still giant lattices.
49. What is the electrical conductivity of an ionic compound?: Ionic
compounds conduct electricity when they're molten or dissolved - but not when
they're solid. The ions in a liquid are free to move and carry a charge. In a solid
they're in a fixed position by the strong ionic bonds.
50. What is the melting point for ionic compounds?: Ionic compounds have
high melting points. The giant ionic lattices are held together by strong electrostatic
forces. It takes lots of energy to overcome these forces, so melting points are very
high.
51. What is the solubility of ionic compounds?: Ionic compounds tend to
dissolve in water. Water molecules are polar - part of the molecule has a small
