Topic 1 - Atomic Structure and the
Periodic Table Questions & Answers
15 The elements in Group 1 of the periodic table are metals. (a) The elements in Group
1 are called the alkali metals. Why are they called the alkali metals?
[2 marks]
(b) Explain the increase in reactivity of elements further down the group.
[4 marks] - ANSWERS(a) because they form hydroxides
that give alkaline solutions (in water)
(b)
the atoms have more electron shells (as move down the group)
so the electron in the outer shell is further away from the nucleus
which reduces the attraction to the nucleus
so the electron is lost more easily from the atom
20(b) Sulfur dioxide dissolves in water. What colour is universal indicator in a solution of
sulfur dioxide? Give a reason for your answer
[2 marks] - ANSWERS(b) red / orange / yellow
because sulfur dioxide (when in solution) is an acid
20(c) Sulfur dioxide is a gas at room temperature. The bonding in sulfur dioxide is
covalent. Explain, in terms of its structure and bonding, why sulfur dioxide has a low
boiling point.
[3 marks] - ANSWERS(c) (there are) weak forces (of attraction)
between the molecules
(these) take little energy to overcome
as the concentration of thiosulfate solution doubles, the rate of reaction doubles. explain
in terms of particles. 3 marks - ANSWERSthe number of particles per unit volume
increases. therefore the frequency of successful collisions increases. so the number of
particles per unit volume doubles and the frequency of collisions doubles.
Q1.The figure below shows magnesium burning in air.
,(b) Name the product from the reaction of magnesium in the figure. - ANSWERS(b)
Magnesium oxide
(c) The magnesium needed heating before it would react. What conclusion can you
draw from this? - ANSWERS(c) The reaction has a high activation energy
1 (e) Why are nanoparticles effective in very small quantities? - ANSWERS(e) They
have a high surface area to volume ratio
1 (f) Give one advantage of using nanoparticles in sun creams. - ANSWERS(f) any one
from:
• Better coverage
• More protection from the Sun's ultraviolet rays
1 g) Give one disadvantage of using nanoparticles in sun creams. - ANSWERS(g) any
one from:
• Potential cell damage to the body
• Harmful effects on the environment
4 (c) Suggest two reasons why 9 carat gold is often used instead of pure gold to make
jewellery. - ANSWERS(c) any two from:
• cost (9 carat is cheaper)
• pure gold is soft or 24 carat gold is soft or 9 carat gold is harder
• can change the colour
Q5.This question is about hydrocarbons.
(a) The names and formulae of three hydrocarbons in the same homologous series are:
Ethane C2H6
Propane C3H8
Butane C4H10
The next member in the series is pentane. What is the formula of pentane? -
ANSWERS(a) C5H12
5 d) Octane (C8H18) is a hydrocarbon found in petrol. Explain why octane is a
hydrocarbon. - ANSWERS(d) contains hydrogen and carbon
(hydrogen and carbon) only
1 (b) Why is aluminium positioned in Group 3 of the periodic table? - ANSWERS(b) has
three electrons in outer energy level / shell
1 (c) In the periodic table, the transition elements and Group 1 elements are metals.
Some of the properties of two transition elements and two Group 1 elements are shown
in the table below.
, Use your own knowledge and the data in the table above to compare the chemical and
physical properties of transition elements and Group 1 elements
[6] - ANSWERSPHYSICAL PROPERTIES
Transition elements
• high melting points
• high densities
• strong
• hard
Group 1
• low melting points
• low densities
• soft
CHEMICAL
Transition elements
• low reactivity / react slowly (with water or oxygen)
• used as catalysts
• ions with different charges
• coloured compounds
Group 1
• very reactive / react (quickly) with water / non-metals
• not used as catalysts
• white / colourless compounds
• only forms a +1 ion
Q2.Rock salt is a mixture of sand and salt.
Salt dissolves in water.
Sand does not dissolve in water.
Some students separated rock salt.
This is the method used.
1. Place the rock salt in a beaker.
2. Add 100 cm3 of cold water.
3. Allow the sand to settle to the bottom of the beaker.
4. Carefully pour the salty water into an evaporating dish.
5. Heat the contents of the evaporating dish with a Bunsen burner until salt crystals start
to form.
Periodic Table Questions & Answers
15 The elements in Group 1 of the periodic table are metals. (a) The elements in Group
1 are called the alkali metals. Why are they called the alkali metals?
[2 marks]
(b) Explain the increase in reactivity of elements further down the group.
[4 marks] - ANSWERS(a) because they form hydroxides
that give alkaline solutions (in water)
(b)
the atoms have more electron shells (as move down the group)
so the electron in the outer shell is further away from the nucleus
which reduces the attraction to the nucleus
so the electron is lost more easily from the atom
20(b) Sulfur dioxide dissolves in water. What colour is universal indicator in a solution of
sulfur dioxide? Give a reason for your answer
[2 marks] - ANSWERS(b) red / orange / yellow
because sulfur dioxide (when in solution) is an acid
20(c) Sulfur dioxide is a gas at room temperature. The bonding in sulfur dioxide is
covalent. Explain, in terms of its structure and bonding, why sulfur dioxide has a low
boiling point.
[3 marks] - ANSWERS(c) (there are) weak forces (of attraction)
between the molecules
(these) take little energy to overcome
as the concentration of thiosulfate solution doubles, the rate of reaction doubles. explain
in terms of particles. 3 marks - ANSWERSthe number of particles per unit volume
increases. therefore the frequency of successful collisions increases. so the number of
particles per unit volume doubles and the frequency of collisions doubles.
Q1.The figure below shows magnesium burning in air.
,(b) Name the product from the reaction of magnesium in the figure. - ANSWERS(b)
Magnesium oxide
(c) The magnesium needed heating before it would react. What conclusion can you
draw from this? - ANSWERS(c) The reaction has a high activation energy
1 (e) Why are nanoparticles effective in very small quantities? - ANSWERS(e) They
have a high surface area to volume ratio
1 (f) Give one advantage of using nanoparticles in sun creams. - ANSWERS(f) any one
from:
• Better coverage
• More protection from the Sun's ultraviolet rays
1 g) Give one disadvantage of using nanoparticles in sun creams. - ANSWERS(g) any
one from:
• Potential cell damage to the body
• Harmful effects on the environment
4 (c) Suggest two reasons why 9 carat gold is often used instead of pure gold to make
jewellery. - ANSWERS(c) any two from:
• cost (9 carat is cheaper)
• pure gold is soft or 24 carat gold is soft or 9 carat gold is harder
• can change the colour
Q5.This question is about hydrocarbons.
(a) The names and formulae of three hydrocarbons in the same homologous series are:
Ethane C2H6
Propane C3H8
Butane C4H10
The next member in the series is pentane. What is the formula of pentane? -
ANSWERS(a) C5H12
5 d) Octane (C8H18) is a hydrocarbon found in petrol. Explain why octane is a
hydrocarbon. - ANSWERS(d) contains hydrogen and carbon
(hydrogen and carbon) only
1 (b) Why is aluminium positioned in Group 3 of the periodic table? - ANSWERS(b) has
three electrons in outer energy level / shell
1 (c) In the periodic table, the transition elements and Group 1 elements are metals.
Some of the properties of two transition elements and two Group 1 elements are shown
in the table below.
, Use your own knowledge and the data in the table above to compare the chemical and
physical properties of transition elements and Group 1 elements
[6] - ANSWERSPHYSICAL PROPERTIES
Transition elements
• high melting points
• high densities
• strong
• hard
Group 1
• low melting points
• low densities
• soft
CHEMICAL
Transition elements
• low reactivity / react slowly (with water or oxygen)
• used as catalysts
• ions with different charges
• coloured compounds
Group 1
• very reactive / react (quickly) with water / non-metals
• not used as catalysts
• white / colourless compounds
• only forms a +1 ion
Q2.Rock salt is a mixture of sand and salt.
Salt dissolves in water.
Sand does not dissolve in water.
Some students separated rock salt.
This is the method used.
1. Place the rock salt in a beaker.
2. Add 100 cm3 of cold water.
3. Allow the sand to settle to the bottom of the beaker.
4. Carefully pour the salty water into an evaporating dish.
5. Heat the contents of the evaporating dish with a Bunsen burner until salt crystals start
to form.
