1
AQA A-LEVEL CHEMISTRY PAPER 1 2026/2027 |
CHEMISTRY | 100 VERIFIED Q&A | DETAILED
RATIONALES | PASS GUARANTEED – A+ GRADED
SECTION 1: ATOMIC STRUCTURE & BONDING - Questions 1-15
Q1: Atomic Number and Mass Number
37
The student is reviewing atomic structure. An atom of 17 Cl contains:
A. 17 protons, 20 neutrons, 17 electrons
B. 17 protons, 17 neutrons, 20 electrons
C. 20 protons, 17 neutrons, 20 electrons
D. 37 protons, 17 neutrons, 37 electrons
Correct Answer: A
Rationale: Atomic number (17) = protons = electrons. Mass number (37) = protons + neutrons, so
neutrons = 37 − 17 = 20. [100% CORRECT]
Q2: Isotopes
The student is reviewing isotopes. Isotopes of an element have:
A. Same number of neutrons, different protons
B. Same number of protons, different neutrons
C. Same mass number, different atomic number
D. Same number of electrons, different protons
Correct Answer: B
Rationale: Isotopes have the same atomic number (protons) but different mass numbers due to
different numbers of neutrons. [100% CORRECT]
Q3: Mass Spectrometry
The student is reviewing mass spectrometry. In a mass spectrometer, ions are separated based on:
A. Mass-to-charge ratio (m/z)
B. Charge only
C. Size only
D. Colour
Correct Answer: A
Rationale: Ions are accelerated, deflected by a magnetic field, and separated according to their
mass-to-charge ratio. [100% CORRECT]
,2
Q4: Electron Configuration
The student is reviewing electron configuration. The electron configuration of a copper atom
( 29 Cu) is:
A. 1𝑠 2 2𝑠 2 2𝑝6 3𝑠 2 3𝑝6 3𝑑9 4𝑠 2
B. 1𝑠 2 2𝑠 2 2𝑝6 3𝑠 2 3𝑝6 3𝑑10 4𝑠1
C. 1𝑠 2 2𝑠 2 2𝑝6 3𝑠 2 3𝑝6 3𝑑10 4𝑠 2
D. 1𝑠 2 2𝑠 2 2𝑝6 3𝑠 2 3𝑝6 3𝑑8 4𝑠 2 4𝑝1
Correct Answer: B
Rationale: Copper has a stable 3𝑑10 4𝑠1 configuration due to the extra stability of a full d subshell.
[100% CORRECT]
Q5: Ionisation Energy
The student is reviewing ionisation energy. The first ionisation energy of an element is:
A. Energy to remove one electron from one mole of gaseous atoms
B. Energy to remove one electron from one mole of solid atoms
C. Energy to add one electron to one mole of gaseous atoms
D. Energy to break one mole of covalent bonds
Correct Answer: A
Rationale: First ionisation energy is the energy required to remove one electron from each atom in
one mole of gaseous atoms to form one mole of gaseous 1+ ions. [100% CORRECT]
Q6: Ionisation Energy Trend
The student is reviewing periodic trends. Why does first ionisation energy generally increase across a
period?
A. Atomic radius increases
B. Nuclear charge increases and shielding remains similar
C. Electrons are added to inner shells
D. Nuclear charge decreases
Correct Answer: B
Rationale: Across a period, nuclear charge increases while shielding stays roughly constant, so the
outer electron is held more strongly. [100% CORRECT]
Q7: Ionic Bonding
The student is reviewing bonding. An ionic bond is:
, 3
A. Electrostatic attraction between oppositely charged ions
B. Sharing of electron pairs
C. Attraction between molecules
D. Metallic attraction
Correct Answer: A
Rationale: Ionic bonding involves electrostatic attraction between positive and negative ions in a
lattice. [100% CORRECT]
Q8: Covalent Bonding
The student is reviewing covalent bonds. A covalent bond is formed by:
A. Transfer of electrons
B. Sharing of a pair of electrons
C. Attraction between ions
D. Delocalised electrons
Correct Answer: B
Rationale: A covalent bond is a shared pair of electrons between two atoms. [100% CORRECT]
Q9: Metallic Bonding
The student is reviewing metallic bonding. Metallic bonding is:
A. Electrostatic attraction between metal ions and delocalised electrons
B. Sharing of electrons between metal atoms
C. Transfer of electrons between metal atoms
D. Hydrogen bonding between metal atoms
Correct Answer: A
Rationale: Metallic bonding consists of a lattice of positive metal ions surrounded by a sea of
delocalised electrons. [100% CORRECT]
Q10: Electronegativity
The student is reviewing electronegativity. Electronegativity is:
A. The ability of an atom to attract the electron pair in a covalent bond
B. The energy required to remove an electron
C. The energy released when an electron is added
D. The size of an atom
Correct Answer: A
Rationale: Electronegativity is the power of an atom to attract the electron pair in a covalent bond.
[100% CORRECT]
AQA A-LEVEL CHEMISTRY PAPER 1 2026/2027 |
CHEMISTRY | 100 VERIFIED Q&A | DETAILED
RATIONALES | PASS GUARANTEED – A+ GRADED
SECTION 1: ATOMIC STRUCTURE & BONDING - Questions 1-15
Q1: Atomic Number and Mass Number
37
The student is reviewing atomic structure. An atom of 17 Cl contains:
A. 17 protons, 20 neutrons, 17 electrons
B. 17 protons, 17 neutrons, 20 electrons
C. 20 protons, 17 neutrons, 20 electrons
D. 37 protons, 17 neutrons, 37 electrons
Correct Answer: A
Rationale: Atomic number (17) = protons = electrons. Mass number (37) = protons + neutrons, so
neutrons = 37 − 17 = 20. [100% CORRECT]
Q2: Isotopes
The student is reviewing isotopes. Isotopes of an element have:
A. Same number of neutrons, different protons
B. Same number of protons, different neutrons
C. Same mass number, different atomic number
D. Same number of electrons, different protons
Correct Answer: B
Rationale: Isotopes have the same atomic number (protons) but different mass numbers due to
different numbers of neutrons. [100% CORRECT]
Q3: Mass Spectrometry
The student is reviewing mass spectrometry. In a mass spectrometer, ions are separated based on:
A. Mass-to-charge ratio (m/z)
B. Charge only
C. Size only
D. Colour
Correct Answer: A
Rationale: Ions are accelerated, deflected by a magnetic field, and separated according to their
mass-to-charge ratio. [100% CORRECT]
,2
Q4: Electron Configuration
The student is reviewing electron configuration. The electron configuration of a copper atom
( 29 Cu) is:
A. 1𝑠 2 2𝑠 2 2𝑝6 3𝑠 2 3𝑝6 3𝑑9 4𝑠 2
B. 1𝑠 2 2𝑠 2 2𝑝6 3𝑠 2 3𝑝6 3𝑑10 4𝑠1
C. 1𝑠 2 2𝑠 2 2𝑝6 3𝑠 2 3𝑝6 3𝑑10 4𝑠 2
D. 1𝑠 2 2𝑠 2 2𝑝6 3𝑠 2 3𝑝6 3𝑑8 4𝑠 2 4𝑝1
Correct Answer: B
Rationale: Copper has a stable 3𝑑10 4𝑠1 configuration due to the extra stability of a full d subshell.
[100% CORRECT]
Q5: Ionisation Energy
The student is reviewing ionisation energy. The first ionisation energy of an element is:
A. Energy to remove one electron from one mole of gaseous atoms
B. Energy to remove one electron from one mole of solid atoms
C. Energy to add one electron to one mole of gaseous atoms
D. Energy to break one mole of covalent bonds
Correct Answer: A
Rationale: First ionisation energy is the energy required to remove one electron from each atom in
one mole of gaseous atoms to form one mole of gaseous 1+ ions. [100% CORRECT]
Q6: Ionisation Energy Trend
The student is reviewing periodic trends. Why does first ionisation energy generally increase across a
period?
A. Atomic radius increases
B. Nuclear charge increases and shielding remains similar
C. Electrons are added to inner shells
D. Nuclear charge decreases
Correct Answer: B
Rationale: Across a period, nuclear charge increases while shielding stays roughly constant, so the
outer electron is held more strongly. [100% CORRECT]
Q7: Ionic Bonding
The student is reviewing bonding. An ionic bond is:
, 3
A. Electrostatic attraction between oppositely charged ions
B. Sharing of electron pairs
C. Attraction between molecules
D. Metallic attraction
Correct Answer: A
Rationale: Ionic bonding involves electrostatic attraction between positive and negative ions in a
lattice. [100% CORRECT]
Q8: Covalent Bonding
The student is reviewing covalent bonds. A covalent bond is formed by:
A. Transfer of electrons
B. Sharing of a pair of electrons
C. Attraction between ions
D. Delocalised electrons
Correct Answer: B
Rationale: A covalent bond is a shared pair of electrons between two atoms. [100% CORRECT]
Q9: Metallic Bonding
The student is reviewing metallic bonding. Metallic bonding is:
A. Electrostatic attraction between metal ions and delocalised electrons
B. Sharing of electrons between metal atoms
C. Transfer of electrons between metal atoms
D. Hydrogen bonding between metal atoms
Correct Answer: A
Rationale: Metallic bonding consists of a lattice of positive metal ions surrounded by a sea of
delocalised electrons. [100% CORRECT]
Q10: Electronegativity
The student is reviewing electronegativity. Electronegativity is:
A. The ability of an atom to attract the electron pair in a covalent bond
B. The energy required to remove an electron
C. The energy released when an electron is added
D. The size of an atom
Correct Answer: A
Rationale: Electronegativity is the power of an atom to attract the electron pair in a covalent bond.
[100% CORRECT]
