AQA CHEMISTRY PAPER 1 2025 MARK SCHEME | FULL
ANSWERS & BREAKDOWN
C1 Atomic Structure - CORRECT ANSWERS-
What are atoms? - CORRECT ANSWERS- Atoms are the particles that make up
everything
What is an element? - CORRECT ANSWERS- An element is a substance in which
all the atoms are the same
Where are elements shown? - CORRECT ANSWERS- Elements are shown in the
Periodic table
How many elements are there? - CORRECT ANSWERS- There are around 118
elements
What is a compound? - CORRECT ANSWERS- A compound is a substance that
contain two or more elements chemically combined
Describe the properties of compounds - CORRECT ANSWERS- The properties of
compounds are usually different to the elements that they are made from
What is a mixture? - CORRECT ANSWERS- A mixture is a substance with different
elements or compounds not chemically combined
,Give an example of a mixture - CORRECT ANSWERS- An example of a mixture is
sand and water as they are not chemically combined and can be separated by
physical means
What is a molecule? - CORRECT ANSWERS- A molecule is a substance that has
any elements chemically joined
What does a chemical formula tell you about a molecule? - CORRECT ANSWERS-
A chemical formula tells the elements in a molecule and the number of atoms of
each element
How is a chemical formula presented? - CORRECT ANSWERS- Each element
symbol starts with a capital letter, if there is a second letter it is in lower case
Give an example of a chemical formula - CORRECT ANSWERS-
What are state symbols? - CORRECT ANSWERS- State symbols show the physical
state of the substance solid (s), liquid (l), gas (g), or dissolved in water (aq)
Name three properties of Metals - CORRECT ANSWERS- -Strong
-Good conductors of heat and electricity
-High melting and boiling points
Name three properties of Non-Metals - CORRECT ANSWERS- -Weak
-Bad conductors of heat and electricity
-Low melting and boiling points
,State the four different ways of separating mixtures - CORRECT ANSWERS- Four
different ways of separating mixtures are filtration, crystallisation, distillation or
chromatography
Describe the process of filtration - CORRECT ANSWERS- Pour your mixture onto
the filter paper, the liquid simply passes through the filter paper into the flask.
The insoluble solid cannot pass through and so it stays on the paper
Describe the process of crystallisation - CORRECT ANSWERS- Use the method of
filtration to filter off any excess soluble solid. Evaporate the mixture then
transfer the hot mixture onto a dish. Crystals are formed when the mixture has
cooled
Describe the process of simple distillation - CORRECT ANSWERS- First we
evaporate the mixture by heating it, the dissolved solid then vaporises. These
vapours condense in the condenser, the dissolved solid then flows into the
beaker and liquid stays in the flask
Describe the process of chromatography - CORRECT ANSWERS- Take a strip of
filter paper and draw a line on the bottom of the paper. Put a small drop of ink
on the line, take a jar full of water up to the line and put the filter paper in. As
the water moves up we see different colours on the paper these are the dyes in
the ink
What were the early ideas of the structure of atoms? - CORRECT ANSWERS-
Early ideas of the structure of atoms stated that they are tiny spheres that
cannot be divided
, What is the plum pudding model? - CORRECT ANSWERS- The plum pudding
model is what scientists suggested is the structure of atoms is after the
discovery of the electron
Describe the plum pudding model - CORRECT ANSWERS- The plum pudding
model suggested that an atom is a ball of positive charge with negative
electrons in embedded in it
Describe how Rutherford carried out the gold foil experiment - CORRECT
ANSWERS- Rutherford took a piece of gold foil, he then fired tiny positive alpha
particles at the gold foil
What did Rutherford observe in the experiment? - CORRECT ANSWERS-
Rutherford observed that most of the particles when straight through the gold
foil and sometimes the alpha particles bounce back of the gold foil
What did Rutherford discover from these observations? - CORRECT ANSWERS-
Rutherford discovered that atoms are mainly empty space as most of the alpha
particles went straight through the gold atoms and that the nucleus of the atom
is very small as only a small number of alpha particles bounce back
Describe the structure of the nuclear model - CORRECT ANSWERS- The nuclear
model states that most of an atom is empty space, in the centre is the nucleus
which contains protons and neutrons around the edge we find electrons
What is the Relative mass and the relative charge of protons, neutrons and
electrons? - CORRECT ANSWERS-
ANSWERS & BREAKDOWN
C1 Atomic Structure - CORRECT ANSWERS-
What are atoms? - CORRECT ANSWERS- Atoms are the particles that make up
everything
What is an element? - CORRECT ANSWERS- An element is a substance in which
all the atoms are the same
Where are elements shown? - CORRECT ANSWERS- Elements are shown in the
Periodic table
How many elements are there? - CORRECT ANSWERS- There are around 118
elements
What is a compound? - CORRECT ANSWERS- A compound is a substance that
contain two or more elements chemically combined
Describe the properties of compounds - CORRECT ANSWERS- The properties of
compounds are usually different to the elements that they are made from
What is a mixture? - CORRECT ANSWERS- A mixture is a substance with different
elements or compounds not chemically combined
,Give an example of a mixture - CORRECT ANSWERS- An example of a mixture is
sand and water as they are not chemically combined and can be separated by
physical means
What is a molecule? - CORRECT ANSWERS- A molecule is a substance that has
any elements chemically joined
What does a chemical formula tell you about a molecule? - CORRECT ANSWERS-
A chemical formula tells the elements in a molecule and the number of atoms of
each element
How is a chemical formula presented? - CORRECT ANSWERS- Each element
symbol starts with a capital letter, if there is a second letter it is in lower case
Give an example of a chemical formula - CORRECT ANSWERS-
What are state symbols? - CORRECT ANSWERS- State symbols show the physical
state of the substance solid (s), liquid (l), gas (g), or dissolved in water (aq)
Name three properties of Metals - CORRECT ANSWERS- -Strong
-Good conductors of heat and electricity
-High melting and boiling points
Name three properties of Non-Metals - CORRECT ANSWERS- -Weak
-Bad conductors of heat and electricity
-Low melting and boiling points
,State the four different ways of separating mixtures - CORRECT ANSWERS- Four
different ways of separating mixtures are filtration, crystallisation, distillation or
chromatography
Describe the process of filtration - CORRECT ANSWERS- Pour your mixture onto
the filter paper, the liquid simply passes through the filter paper into the flask.
The insoluble solid cannot pass through and so it stays on the paper
Describe the process of crystallisation - CORRECT ANSWERS- Use the method of
filtration to filter off any excess soluble solid. Evaporate the mixture then
transfer the hot mixture onto a dish. Crystals are formed when the mixture has
cooled
Describe the process of simple distillation - CORRECT ANSWERS- First we
evaporate the mixture by heating it, the dissolved solid then vaporises. These
vapours condense in the condenser, the dissolved solid then flows into the
beaker and liquid stays in the flask
Describe the process of chromatography - CORRECT ANSWERS- Take a strip of
filter paper and draw a line on the bottom of the paper. Put a small drop of ink
on the line, take a jar full of water up to the line and put the filter paper in. As
the water moves up we see different colours on the paper these are the dyes in
the ink
What were the early ideas of the structure of atoms? - CORRECT ANSWERS-
Early ideas of the structure of atoms stated that they are tiny spheres that
cannot be divided
, What is the plum pudding model? - CORRECT ANSWERS- The plum pudding
model is what scientists suggested is the structure of atoms is after the
discovery of the electron
Describe the plum pudding model - CORRECT ANSWERS- The plum pudding
model suggested that an atom is a ball of positive charge with negative
electrons in embedded in it
Describe how Rutherford carried out the gold foil experiment - CORRECT
ANSWERS- Rutherford took a piece of gold foil, he then fired tiny positive alpha
particles at the gold foil
What did Rutherford observe in the experiment? - CORRECT ANSWERS-
Rutherford observed that most of the particles when straight through the gold
foil and sometimes the alpha particles bounce back of the gold foil
What did Rutherford discover from these observations? - CORRECT ANSWERS-
Rutherford discovered that atoms are mainly empty space as most of the alpha
particles went straight through the gold atoms and that the nucleus of the atom
is very small as only a small number of alpha particles bounce back
Describe the structure of the nuclear model - CORRECT ANSWERS- The nuclear
model states that most of an atom is empty space, in the centre is the nucleus
which contains protons and neutrons around the edge we find electrons
What is the Relative mass and the relative charge of protons, neutrons and
electrons? - CORRECT ANSWERS-
