AQA AS Level Chemistry Paper 1 QUESTIONS AND ANSWERS LATEST 2025 CORRECT
VERIFIED ANSWERS
What is the charge of a proton? -CORRECT ANSWER-+1
What is the charge of a neutron? -CORRECT ANSWER-0
What is the charge of an electron? -CORRECT ANSWER--1
What is the mass of a proton? -CORRECT ANSWER-1
What is the mass of a neutron? -CORRECT ANSWER-1
What is the mass of an electron? -CORRECT ANSWER-1/1800
What is an isotope? -CORRECT ANSWER-Isotopes of an element are atoms with the same
number of protons but different numbers of neutrons.
Why do isotopes of an element all have the same chemical properties? -CORRECT ANSWER-
This is because chemical properties are decided by the number and arrangements of
electrons and all isotopes of an element have the same number of electrons.
Why do isotopes of an element have different physical properties? -CORRECT ANSWER-This
is because physical properties are decided by the mass number and isotopes of an element
have different mass numbers.
,What is the first stage in time of flight mass spectrometry and what are the 2 ways it can
occur? -CORRECT ANSWER-1. Electron spray ionisation
2.Electron impact ionisation
What is electron spray ionisation? -CORRECT ANSWER-The sample is dissolved and pushed
through a small nozzle at high pressure. A high voltage is applied to it causing each particle
to gain a + ion so that the gas is made up of positive ions.
What is electron impact ionisation? -CORRECT ANSWER-The sample is vaporised and an
electron gun is used to fire high energy electrons which knocks of 1 electron of each particle
so they become positive ions.
What is the second stage in time of flight mass spectrometry? -CORRECT ANSWER-
Acceleration
What happens in the acceleration stage of time of flight mass spectrometry? -CORRECT
ANSWER-The positively charged ions are accelerated by an electric field so that they all have
the same kinetic energy which means that the lighter ions will move faster than the heavier
ions.
What is the third stage in time of flight mass spectrometry? -CORRECT ANSWER-Ion drift
What happens in the ion drift stage of time of flight mass spectrometry? -CORRECT
ANSWER-The ions enter a region with no electric field, so they just drift through it. Lighter
ions will drift through faster than heavier ions.
What is the final stage of time of flight mass spectrometry? -CORRECT ANSWER-Detection
What happens in the detection stage of time of flight mass spectrometry? -CORRECT
ANSWER-Because ions have a lower mass/charge ratio travel at a higher speed in the drift
region, they reach the detector in less time than ions with a higher mass/charge ratio. The
detector detects charged particles and a mass spectrum is produced.
, What is the electronic configuration of calcium? -CORRECT ANSWER-
1s2,2s2,2p6,3s2,3p6,4s2
What is the electronic configuration of chromium? -CORRECT ANSWER-
1s2,2s2,2p6,3s2,3p6,3d5,4s1
What is the first ionisation energy? -CORRECT ANSWER-The first ionisation energy needed to
remove one electron from each atom in 1 mole of gaseous atoms to form 1 mole of +1
gaseous ion..
How does nuclear charge affect ionisation energy? -CORRECT ANSWER-More protons means
more positively charged means the stronger the attraction for electrons.
How does distance from the nucleus affect ionisation energy? -CORRECT ANSWER-The closer
the electron is to the nucleus, the stronger the attraction.
How does shielding affect ionisation energy? -CORRECT ANSWER-As the number of electrons
between outer electrons and the nucleus increases, the outer electron feels less attraction
towards the nuclear charge.
What is the trend in ionisation energy down a group? -CORRECT ANSWER-The first ionisation
energy down a group has a general decrease because down a group each element has an
extra electron shell compared to the one above so the extra inner shells will shield the outer
electrons from the nucleus attraction.
What is the trend in ionisation energy across a period? -CORRECT ANSWER-The first
ionisation energy across a period has a general increase because it gets harder to remove
outer shell electrons.
What is the definition of relative atomic mass (Ar)? -CORRECT ANSWER-The relative atomic
mass is the average mass of an atom of an element on a scale where an atom of carbon-12 is
12.
VERIFIED ANSWERS
What is the charge of a proton? -CORRECT ANSWER-+1
What is the charge of a neutron? -CORRECT ANSWER-0
What is the charge of an electron? -CORRECT ANSWER--1
What is the mass of a proton? -CORRECT ANSWER-1
What is the mass of a neutron? -CORRECT ANSWER-1
What is the mass of an electron? -CORRECT ANSWER-1/1800
What is an isotope? -CORRECT ANSWER-Isotopes of an element are atoms with the same
number of protons but different numbers of neutrons.
Why do isotopes of an element all have the same chemical properties? -CORRECT ANSWER-
This is because chemical properties are decided by the number and arrangements of
electrons and all isotopes of an element have the same number of electrons.
Why do isotopes of an element have different physical properties? -CORRECT ANSWER-This
is because physical properties are decided by the mass number and isotopes of an element
have different mass numbers.
,What is the first stage in time of flight mass spectrometry and what are the 2 ways it can
occur? -CORRECT ANSWER-1. Electron spray ionisation
2.Electron impact ionisation
What is electron spray ionisation? -CORRECT ANSWER-The sample is dissolved and pushed
through a small nozzle at high pressure. A high voltage is applied to it causing each particle
to gain a + ion so that the gas is made up of positive ions.
What is electron impact ionisation? -CORRECT ANSWER-The sample is vaporised and an
electron gun is used to fire high energy electrons which knocks of 1 electron of each particle
so they become positive ions.
What is the second stage in time of flight mass spectrometry? -CORRECT ANSWER-
Acceleration
What happens in the acceleration stage of time of flight mass spectrometry? -CORRECT
ANSWER-The positively charged ions are accelerated by an electric field so that they all have
the same kinetic energy which means that the lighter ions will move faster than the heavier
ions.
What is the third stage in time of flight mass spectrometry? -CORRECT ANSWER-Ion drift
What happens in the ion drift stage of time of flight mass spectrometry? -CORRECT
ANSWER-The ions enter a region with no electric field, so they just drift through it. Lighter
ions will drift through faster than heavier ions.
What is the final stage of time of flight mass spectrometry? -CORRECT ANSWER-Detection
What happens in the detection stage of time of flight mass spectrometry? -CORRECT
ANSWER-Because ions have a lower mass/charge ratio travel at a higher speed in the drift
region, they reach the detector in less time than ions with a higher mass/charge ratio. The
detector detects charged particles and a mass spectrum is produced.
, What is the electronic configuration of calcium? -CORRECT ANSWER-
1s2,2s2,2p6,3s2,3p6,4s2
What is the electronic configuration of chromium? -CORRECT ANSWER-
1s2,2s2,2p6,3s2,3p6,3d5,4s1
What is the first ionisation energy? -CORRECT ANSWER-The first ionisation energy needed to
remove one electron from each atom in 1 mole of gaseous atoms to form 1 mole of +1
gaseous ion..
How does nuclear charge affect ionisation energy? -CORRECT ANSWER-More protons means
more positively charged means the stronger the attraction for electrons.
How does distance from the nucleus affect ionisation energy? -CORRECT ANSWER-The closer
the electron is to the nucleus, the stronger the attraction.
How does shielding affect ionisation energy? -CORRECT ANSWER-As the number of electrons
between outer electrons and the nucleus increases, the outer electron feels less attraction
towards the nuclear charge.
What is the trend in ionisation energy down a group? -CORRECT ANSWER-The first ionisation
energy down a group has a general decrease because down a group each element has an
extra electron shell compared to the one above so the extra inner shells will shield the outer
electrons from the nucleus attraction.
What is the trend in ionisation energy across a period? -CORRECT ANSWER-The first
ionisation energy across a period has a general increase because it gets harder to remove
outer shell electrons.
What is the definition of relative atomic mass (Ar)? -CORRECT ANSWER-The relative atomic
mass is the average mass of an atom of an element on a scale where an atom of carbon-12 is
12.
