CHANGES:
Chemical reactions
Use
these questions to help you revise.
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QUESTIONS |
ANSWER BOX |
|
1. |
Name
the three states of matter. |
solid,
liquid, gas |
2. |
Which
state of matter has a fixed shape? |
solid |
3. |
Which
state of matter has most space between the particles? |
gas |
4. |
Which
is more dense, cold air or warm air? |
cold
air |
5. |
Smells
can spread around a room because gas particles through the air. |
diffuse |
6. |
Describe
the movement of particles in a solid. |
they
vibrate |
7. |
Describe
the movement of particles in a gas. |
they
move around very quickly |
8. |
What
do we call it when a solid turns into a liquid? |
melting |
9. |
What
do we call it when a liquid turns into a solid? |
freezing |
10.
|
Which
of these changes needs you to supply energy? |
boiling,
melting |
|
boiling,
freezing, melting |
|
11.
|
What
does 'condense' mean? |
when
a gas turns to liquid |
12.
|
What
is the opposite of 'condense'? |
evaporate
(boil) |
13. |
What
do we call a liquid which dissolves a substance? |
a
solvent |
14.
|
What
is the solute in a solution of sugar? |
sugar |
15.
|
What
can you say about the mass of substances before and after; |
|
|
a)
a chemical change? and, |
a)
they are the same |
|
b)
a physical change? |
b)
they are the same |
16.
|
Complete
this equation; |
|
|
acid
+ base --> + |
salt
+ water |
17.
|
Complete
the word equation; |
|
|
Sulphuric
acid + copper oxide --- > + |
copper sulphate + water |
18.
|
Which
gas is given off when a metal reacts with an acid? |
hydrogen |
19.
|
What
do we call a reaction that gives out energy? |
exothermic |
20.
|
What
are the three main elements in fertiliser? |
nitrogen,
phosphorus,potassium |
21.
|
What
is the chemical formula for carbon dioxide? |
C02 |
22.
|
What
is another word for combustion? |
burning
(oxidation) |
23.
|
Which
type of change, chemical or physical, is no new substance made? |
physical |
24. |
The
test for carbon dioxide is when it turns a liquid milky. Which liquid? |
lime
water |
25.
|
Which
gas causes a pop when lit with a splint? |
hydrogen |