AQA Chemistry As Level Paper 1
1. State the electron rules <Ans> Lowest energy filled first (3d>4s) Line
up parallel
Single until forced to pair
2. Electronegativity <Ans> The ability of an atom to attract electrons within a covalent bond
3. RAM (relative atomic mass) <Ans> Average mass of one atom compared to 1/12th the mass of a c-
12 atom
-
4. Ionisation energy <Ans> The energy required to remove one mole of electrons from each of one
mole of gaseous atoms to form one mole of positive gaseous ions (Endothermic)
5. Trends of Ionisation Energy <Ans> Across a period, i.e increases as there is no increase in
shielding but an increase in atomic number
Decrease down a group due to increased shielding reducing the electrostatic force of attraction from the
nucleus
6. Drop at 2,3 <Ans> Al - Between groups 2,3... first electron in p orbital
- increase in shielding
- reduce forces of attraction
- less energy required to remove
7. Drop at 4,5 <Ans> P - between groups 4-5 there is a drop
- First electron pairing
1/9
, - increased repulsion
- less energy is required to remove an eleccte
8. Isotopes <Ans> Atoms with the same atomic number but a different mass number
- do not react differently as same electron configuration
9. Factors Affecting I.E <Ans> -Atomic Radius
-Shielding
-Effective Nuclear Charge
-Proton Number
10. Not 100% yield because... <Ans> Incomplete Reactions
Unwanted side reactions
Products lost as gases
11. Ice less dense than water <Ans> Water - hydrogen bonds continuously broken and reformed
Ice - hydrogen bonds kept in a fixed position so are slightly longer Increased distance causes
ice to be less dense and float
12. Enthalpy <Ans> Measure of heat content of a substance under constant conditions
13. Endothermic reaction <Ans> Heat is given off
Negative enthalpy
2/9
1. State the electron rules <Ans> Lowest energy filled first (3d>4s) Line
up parallel
Single until forced to pair
2. Electronegativity <Ans> The ability of an atom to attract electrons within a covalent bond
3. RAM (relative atomic mass) <Ans> Average mass of one atom compared to 1/12th the mass of a c-
12 atom
-
4. Ionisation energy <Ans> The energy required to remove one mole of electrons from each of one
mole of gaseous atoms to form one mole of positive gaseous ions (Endothermic)
5. Trends of Ionisation Energy <Ans> Across a period, i.e increases as there is no increase in
shielding but an increase in atomic number
Decrease down a group due to increased shielding reducing the electrostatic force of attraction from the
nucleus
6. Drop at 2,3 <Ans> Al - Between groups 2,3... first electron in p orbital
- increase in shielding
- reduce forces of attraction
- less energy required to remove
7. Drop at 4,5 <Ans> P - between groups 4-5 there is a drop
- First electron pairing
1/9
, - increased repulsion
- less energy is required to remove an eleccte
8. Isotopes <Ans> Atoms with the same atomic number but a different mass number
- do not react differently as same electron configuration
9. Factors Affecting I.E <Ans> -Atomic Radius
-Shielding
-Effective Nuclear Charge
-Proton Number
10. Not 100% yield because... <Ans> Incomplete Reactions
Unwanted side reactions
Products lost as gases
11. Ice less dense than water <Ans> Water - hydrogen bonds continuously broken and reformed
Ice - hydrogen bonds kept in a fixed position so are slightly longer Increased distance causes
ice to be less dense and float
12. Enthalpy <Ans> Measure of heat content of a substance under constant conditions
13. Endothermic reaction <Ans> Heat is given off
Negative enthalpy
2/9
