8/12/2019 State, Describe, Explain
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State, Describe, Explain.
As you go through the questions they require more detail and a
better understanding
of the topic. The number of marks available can also tell you
what you need to
include in the answer.
Examples:
1. State the difference between a solid and a liquid with
regards to their physical
structure. (1 mark)
A solid maintains its shape and a liquid takes the shape of its
container (1).
2. Describe the difference between a solid and a liquid with
regards to their physical
structure. (2 marks)
Particles in a solid are tightly packed and in a regular
formation (1). In a liquidthe particles are free flowing and can
move around each other (1).
3. Explain the difference between a solid and a liquid with
regards to their physical
structure. (3 marks)
Particles in a solid are tightly packed (1*), this is because of
strong forces that
hold the particles together (1). Particles in a liquid can move
around each other
(1*) because the forces that hold them together are weaker
(1).
*Either of these can be used, you do not have to include both
descriptions.
Questions:
Use the examples above to help you answer the following
questions.
All
1. State the difference between a liquid and a gas. (1 mark)2.
State what initially happens to a solid when it is heated. (1
mark)3. State the name of the process given to perfume travelling
through a
room. (1 mark)4. State the name of the process of a gas turning
into a liquid. (1 mark)5. State what an indicator does. (1
mark)
Most
6. Describe what happens to the particles in a solid when it is
heated. (2marks)
7. Describe what happens to the particles in Ribena when they
areadded to water. (2 marks)
8. Describe what happens when a solid turns into a liquid (2
marks)9. Describe what happens to the pH when an acid is added to
an alkali.
(2 marks)
10.Describe the hazard symbol given to acids. (2 marks)S
ome
11.Explain why a liquid cannot be compressed but a gas can. (3
marks)12.Explain why diffusion cannot happen in solids. (3
marks)13.Explain what happens when a liquid turns into a gas. (3
marks)
8/12/2019 State, Describe, Explain
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14.Explain the reason for using Universal Indicator instead of
Litmus. (3marks)
15.Explain what is meant by neutralisation. (3
marks)Answers:
Use the following mark scheme to help you mark and improve your
answers. Firstly
work out where you may have lost marks and then, in a different
colour, add your
improvement.
1. A liquid takes the shape of the bottom of its container and a
liquid expands tofill the whole of the container (1).
2. A solid will expand when it is heated (1).3. Perfume can
travel across a room because of diffusion (1).4. When a gas turns
into a liquid it is called condensation (1).5. An indicator tells
us whether a substance is an acid or an alkali (1).
6. The particles in a solid gain thermal energy when heated (1),
this causes themto vibrate more expanding the gaps between them
(1).
7. When Ribena particles are added to water they mix together
(1), this is calleddiffusion (1).
8. When a solid turns into a liquid it has melted (1), the
particles have gainedenough thermal energy so that they can move
around each other (1).
9. When an acid is added to an alkali the pH gets lower (1), the
solution willbecome acidic (1).
10.The hazard symbol given to acids is corrosive (1), this means
it causesdamage to living tissue (1).
11.A liquid cannot be compressed because its particles are
tightly packedtogether (1). In a gas the particles are spread out
(1) so there are gaps
between them, which can be compressed (1).
12.Diffusion cannot happen in a solid because the particles
cannot move aroundeach other (1). In a liquid and a gas the
particles are free flowing (1), which
means the particles can mix together (1).
13.When a liquid turns into a gas it is called evaporation (1).
This happensbecause the particles gain so much thermal energy (1)
that the force holding
them together are overcome (1).
14.Universal Indicator is more useful than Litmus because it
gives us a range ofcolours (1*), this can tell us how strong or
weak and acid or an alkali is (1).
Litmus only has two colour changes (1*), it can only tell us
whether the
solution is acid, alkali or neutral (1).
15.Neutralisation occurs when an acid and alkali are added
together (1) andmake a salt (1) and water (1).
Snap:
