C4 – Chemical patterns
Q1
Question
What does the nucleus of an atom
contain?
Answer:
Protons and neutrons.
C4 – Chemical patterns
Q2
Question
What is the relative mass and charge
of a neutron?
Answer:
Relative mass: 1
Charge: 0
C4 – Chemical patterns
C4 – Chemical patterns
Q3
Question
What are the state symbols for each
physical state?
Answer:
Solid (s)
Liquid (l)
Gas (g)
Dissolved in water (aq)
Q4
Question
Balance these equations:
a) Na + Cl2 → NaCl
b) K + H2O → KOH + H2
Answer:
a) 2Na + Cl2 → 2NaCl
b) 2K + 2H2O → 2KOH + H2
C4 – Chemical patterns
Q5
Question
Describe how heating a metal can help
to identify it.
Answer:
When metals are heated they produce
flames with distinctive colours.
C4 – Chemical patterns
Q6
Question
Why does each element produce a
different line spectrum?
Answer:
Each element has a different electron
arrangement. When heated the
electrons are excited and release
energy as light.
C4 – Chemical patterns
C4 – Chemical patterns
Q7
Question
What can line spectrums be used for
and what is this technique called?
Answer:
Line spectrums can be used to identify
elements. This is called spectroscopy.
Q8
Question
What size groups did Döbereiner
organise the elements into? What were
these groups called?
Answer:
Three
Triads
C4 – Chemical patterns
Q9
Question
Give two reasons why Newlands’
Octaves were criticised.
Answer:
• He assumed that all the elements
had been discovered.
• He put elements with different
properties in the same group.
• He put 2 elements in the same
position in some cases.
C4 – Chemical patterns
Q10
Question
Why did Mendeleev leave gaps in his
Table of Elements?
Answer:
They were for undiscovered elements.
C4 – Chemical patterns
C4 – Chemical patterns
Q11
Question
What feature of atoms determines the
order of the periodic table.
Answer:
Proton number.
Q12
Question
What is significant about the
properties of elements in the same
group?
Answer:
They are similar – this means that you
can predict properties of other
elements in that group.
C4 – Chemical patterns
Q13
Question
What are the rows in the periodic table
known as?
Answer:
Periods.
C4 – Chemical patterns
Q14
Question
Oxygen can be written as 168O. How
many protons does one atom of oxygen
contain?
Answer:
8
C4 – Chemical patterns
C4 – Chemical patterns
Q15
Question
How many electrons can the first and
second shell of any atom hold?
Answer:
First: 2
Second: 8
Q16
Question
Draw the electron configuration of
carbon.
Answer:
C4 – Chemical patterns
Q17
C4 – Chemical patterns
Q18
Question
Explain why atoms in Group 1 form positive
ions and atoms in Group 7 form negative
ions.
Answer:
Atoms in Group 1 have 1 electrons in their
outer shell, when they lose an electron to
make a full outer shell, they form positive
ions.
Atoms in Group 7 have 7 electrons in their
outer shell. When they gain an electron to
form a full outer shell they form positive
ions.
Question
What is ionic bonding?
Answer:
In ionic bonding, atoms gain or lose
electrons to form ions. Ions are
strongly attracted to one another
because of the attraction of opposite
charges.
C4 – Chemical patterns
C4 – Chemical patterns
Q19
Question
What kind of structures do ionic
compounds form?
Answer:
Giant ionic lattices.
Q20
Question
The formula of magnesium bromide is
MgBr2. The charge on the bromide
ion is 1-. What is the charge on the
magnesium ion?
Answer:
2+
C4 – Chemical patterns
Q21
Question
The charge on the iron (III) ion is 3+,
the charge on the oxygen ion is 2-.
What is the formula for iron (III)
oxide?
Answer:
Fe2O3
C4 – Chemical patterns
Q22
Question
The charge on the sodium ion is 1+,
the charge on the carbonate ion is 2-.
What is the formula for sodium
carbonate?
Answer:
Na2CO3
C4 – Chemical patterns
C4 – Chemical patterns
Q23
Question
Which group are the alkali metals?
Answer:
Group 1
Q24
Question
As you go down the group of alkali
metals, do they become more or less
reactive?
Answer:
More reactive.
C4 – Chemical patterns
Q25
Question
Describe the reactions of the alkali
metals with water.
Answer:
Reactivity increases as you move down
the group. Lithium, sodium and
potassium react vigorously – move
around, fizzing. They produce
hydrogen gas and form hydroxides.
C4 – Chemical patterns
Q26
Question
Write a balanced equation for the
reaction between lithium and chlorine.
Include state symbols.
Answer:
2Li (s) + Cl2 (g) → 2LiCl (s)
C4 – Chemical patterns
C4 – Chemical patterns
Q27
Question
Atoms of Group 7 elements tend to go
round in pairs. What word describes
this type of molecule?
Answer:
Diatomic
Q28
Question
Describe how the reactivity of the
Group 7 elements changes as you go
down the group.
Answer:
As you move down the group they
become less reactive.
C4 – Chemical patterns
Q29
Question
Describe the appearance of chlorine at
room temperature.
Answer:
Chlorine is a dense green gas.
C4 – Chemical patterns
Q30
Question
Name a type of experiment that could
be used to determine the relative
reactivity of the halogens.
Answer:
You could use displacement reactions.
For example, you could displace
bromine from solutions of bromides
usng chlorine.
C4 – Chemical patterns
C4 – Chemical patterns
Q31
Question
What does this hazard symbol mean?
Give an example of a substance that
would need this symbol on its label.
Answer:
Corrosive.
Attacks and destroys living tissue.
Examples: concentrated acid e.g.
sulfuric acid.
Q32
Question
What precautions would you need to
take when working with Group 7
elements? Why?
Answer:
Use inside a fume cupboard.
They are toxic.