Chemistry Reference
In-Depth Information
Atomic structure and bonding
●
Additional questions
1 a
Define the terms: proton, neutron and electron.
b
An atom
X
has a proton number of 19 and
relative atomic mass of 39.
(iii)
How many electrons, protons and neutrons
are there in an atom of
X
?
(iii)
How many electrons will there be in the
outer energy level (shell) of an atom of
X
?
(iii)
What is the electronic configuration of
X
?
2 a
6
31
Ga and
7
31
Ga are isotopes of gallium.
With reference to this example, explain what you
understand by the term isotope.
b
A sample of gallium contains 60% of atoms of
69
O
H
H
C
C
H
O
H
c
Between which two atoms is there a double
covalent bond?
d
How many single covalent bonds does each
carbon atom have?
e
Write a paragraph explaining the sorts of properties
you would expect this substance to have.
7
The elements sodium and chlorine react together
to form the compound sodium chloride, which has
a giant ionic lattice structure.
a
What type of structure do the elements
(iii)
sodium and
(iii)
chlorine have?
b
Draw a diagram to represent how the ions are
arranged in the crystal lattice of sodium chloride.
c
Explain how the ions are held together in this
crystal lattice.
d
Draw diagrams to show how the electrons are
arranged in a sodium ion and a chloride ion.
(The proton numbers of sodium and chlorine
are 11 and 17, respectively.)
e
Make a table showing the properties of the
three substances sodium, chlorine and sodium
chloride. Include in your table:
(iii)
the physical state at room temperature
(iii)
solubility in (or reaction with) water
(iii)
colour
(iv)
electrical conductivity.
8
Explain the following.
a
Ammonia is a gas at room temperature.
b
The melting points of sodium chloride and
iodine are very different.
c
Metals generally are good conductors of electricity.
d
Buckminsterfullerene is an allotrope of carbon.
e
Graphite conducts electricity but diamond
does not.
31
Ga and 40% of atoms of
7
31
Ga. Calculate the
relative atomic mass of this sample of gallium.
3
Draw diagrams to show the bonding in each of the
following compounds:
a
calcium fluoride (CaF
2
)
b
oxygen (O
2
)
c
magnesium chloride (MgCl
2
)
d
tetrachloromethane (CCl
4
).
4
Use the information given in Table 3.6 on p. 43 to
work out the formula for:
a
silver oxide
b
zinc chloride
c
potassium sulfate
d
calcium nitrate
e
iron(
ii
) nitrate
f
copper(
ii
) carbonate
g
iron(
iii
) hydroxide
h
aluminium fluoride.
5
Atoms of elements
X
,
Y
and
Z
have 16, 17 and
19 electrons, respectively. Atoms of argon have
18 electrons.
a
Determine the formulae of the compounds
formed by the combination of the atoms of the
elements:
(iii)
X
and
Z
(iii)
Y
and
Z
(iii)
X
with itself.
b
In each of the cases shown in
a(ii)
-
(iii)
above,
name the type of chemical bond formed.
c
Give two properties you would expect to be shown
by the compounds formed in
a(ii)
and
a(iii)
.
6
The diagram shows the arrangement of the outer
electrons only in a molecule of ethanoic acid.
a
Name the different elements found in this
compound.
b
What is the total number of atoms present in this
molecule?
