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ChemistryKS4 Atomic Structure and

the Periodic Table Homework Booklet

Name: _________________________________________Class: _________________________________________Teacher: _______________________________________

Homework Task Due Date

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As01 AtomsAs02 Chemical EquationsAs03 Separating MixturesAs04 Fractional Distilation and Paper ChromatographyAs05 History of the AtomAs06 Structure of the AtomAs07 Electronic StructureAs08 IonsAs09 IsotopesAs10 Devlopment of the Periodic TableAs11 Electronic Structure and the Periodic TableAs12 The Alkali MetalsAs13 Group 7 – HalogensAs14 Explaining TrendsAs15 The Transition Elements

As 0

1

Atoms R A G The definition of an element, an atom and a compound

The basic structure of an atom

How elements are arranged on the periodic table

How to estimate the size and scale of atoms in metres and nanometres

Read the As01 sections on your knowledge organisers before you begin.

Comprehension Task 1. Draw and label an atom. You should have four labels.

2. Connect each key word to the correct definition.

Atom

Element

Compound

A group of atoms that each have the same number of protons.

Two or more elements chemically combined in fixed proportions and can be represented by formulae.

The smallest part of an element that can exist.

As01 Atoms Exam Question Practise

The figure below represents the structure of a lithium atom.

(a) Name the particle in the atom that has a positive charge.

(1)

(b) Name the particle in the atom that has the smallest mass.

(1)

(c) Protons are in the nucleus.

Which other sub-atomic particles are in the nucleus?

Tick (✔) one box.

Ions

Molecules

neutrons

(1)

(d) The radius of an atom is 0.2 nm

The radius of the nucleus is the radius of the atom.

Calculate the radius of the nucleus.

Give your answer in standard form.

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

Radius = ______________________ nm

(2)

Type Here

Type Here

Type Here

Type Here

Type Here

Type Here

Type Here

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Q2.

(a) Draw one line from each substance to a description of the substance.

(1)

Q3.

(a) Complete the sentence.

Aluminium is an element because aluminium is made of

only one type of _________________________ .

(1)

(b) Figure 1 shows the electronic structure of an aluminium atom.

Use the correct words from the box to complete the sentence.

electrons ions protons neutrons shells

The nucleus of an aluminium atom contains _______________ and

_______________.

(2)

Type Here

Type Herel

Type Herel

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Chemical Equations R A G What happens to atoms in chemical reactions How the mass of reactants compares to the mass of

products in a chemical reaction. Why mass appears to change in some chemical reactions

involving gases How to write balanced symbol equations, including state

symbols


Comprehension Task 1. What is the law of conservation?

2. For the following reactions, state the missing mass and explain why the observed mass of the reaction will increase or decrease:

Burning magnesium in oxygen

Equation: 2Mg(s) + O2(g) 2MgO(s)

Masses: 1.62g 1.75g

Explanation

Reacting calcium carbonate with Hydrochloric Acid

Equation CaCO3(s) + 2HCl(aq) CaCl2(aq) + CO2(g) + H2O(l)

Masses: 3.2g 1.1g 1.3g 0.9g

Explanation:

Reacting Magnesium with Hydrochloric Acid

Equation Mg(s) + 2HCl(aq) MgCl2(aq) + H2(g)

Masses: 2.43g 3.65g 0.20g

Explanation

As02 Chemical Equations Exam Question Practise

Q1. A student investigated the law of conservation of mass.

The law of conservation of mass states that the mass of the products is equal to the mass of the reactants.

This is the method used.1. Pour lead nitrate solution into a beaker labelled A.2. Pour potassium chromate solution into a beaker labelled B.3. Measure the mass of both beakers and contents.4. Pour the solution from beaker B into beaker A.5. Measure the mass of both beakers and contents again.

When lead nitrate solution and potassium chromate solution are mixed, a reaction takes place.

This is the equation for the reaction:

Pb(NO3)2(aq) + K2CrO4(aq) ⟶ PbCrO4(s) + 2KNO3(aq)

(a) What would the student see when the reaction takes place?

___________________________________________________________________

___________________________________________________________________

(1)

(b) The table shows the student’s results.

Mass in g

Beaker A and contents before mixing 128.71

Beaker B and contents before mixing 128.97

Beaker A and contents after mixing 154.10

Beaker B after mixing 103.58

Show that the law of conservation of mass is true.

Use the data from the table above.

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

(2)

Two lines

Four lines

(c) What is the resolution of the balance used to obtain the results in the table?

Tick (✔) one box.

0.01 g 0.1 g 1 g 100 g

(1)

(d) Another student also tests the law of conservation of mass using the same method.

The student uses a different reaction.

This is the equation for the reaction.

Na2CO3(aq) + 2HCI(aq) ⟶ 2NaCl(aq) + CO2(g) + H2O(I)

Explain why this student’s results would not appear to support the law of conservation of mass.

(3)

Q2. Complete the balanced equation for the reaction oxygen hydrogen in a hydrogen fuel cell.

H2 + ⟶ H2O(2)

Type Heree

Type Heree

Type Heree

Type Heree

Type Here

Type Heree

Type Heree

Type Heree

As 0

3Separating Mixtures R A G

What a mixture is How to separate mixtures using filtration, crystallisation

and distillation


Comprehension Task 1. For each of the diagrams below, state whether they are an element, a compound or a

mixture.

2. Connect each mixture to a method you would use to separate it.

Sea water

Ink

Excess, undissolved salt in water

Filtration

Crystallisation

Distillation

A

B

C

D

E

F

G

H

I

As03 Separating Mixtures Exam Question Practise

Q1.This question is about mixtures.

(a) Substances are separated from a mixture using different methods.

Draw one line from each substance and mixture to the best method of separation.

Substance and mixture Method of separation

Chromatography

Ethanol from ethanol and water Crystallisation

Salt from sea water Electrolysis

The different colours in black ink Filtration

Fractional distillation

(3)

(b) A student filters a mixture.

Figure 1 shows the apparatus.

Figure 1

Suggest one improvement to the apparatus.

(1)

(c) Complete the sentences.

Choose answers from the box.

condense evaporate freeze melt solidify

In simple distillation, the mixture is heated to make the liquid

The vapour is then cooled to make it

(2)

Figure 2 shows the arrangement of atoms in a pure metal and in a mixture of metals.

Figure 2

(d) Calculate the percentage of metal B atoms in the mixture of metals shown in Figure 2.

Percentage of metal B atoms = %

(2)

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Fractional distillation and paper chromatography Why fractional distillation is needed to separate some

liquids How fractional distillation works How paper chromatography works


Comprehension Task 1. Complete the zen diagram to show the similarities and differences of fractional

distillation and paper chromatography

Fractional Distillation Paper Chromatography

2. Give the order in which these liquids will be separated from a mixture of them using fractional distillation:

Water Acetic Acid Benzene Acetone Ethyl alcohol100C 118C 80C 39C 78C

As04 Fractional distillation and paper chromatography Exam Question Practise

Q1.A student investigated the colours in three different flowers, A, B and C.

The colours are soluble in ethanol but are insoluble in water.

This is the method used.

1. Crush flower A.2. Add ethanol to flower A.3. Filter the mixture.4. Put spots of the coloured filtrate on to the chromatography paper.5. Repeat steps 1-4 with flowers B and C.

Figure 1 shows the apparatus used.

Figure 1

(a) The student made two mistakes in setting up the apparatus.

Give one problem caused by each mistake.

Mistake 1

Problem caused

Mistake 2

Problem caused

(4)

(b) Another student set up the apparatus correctly.

Figure 2 represents the student’s results.

Figure 2

Give two conclusions you can make from Figure 2.

1.

2.

(2)

Q2.

Ethanol has a boiling point of 78 °C.

Water has a boiling point of 100 °C.

Describe how distillation is used to separate a mixture of ethanol and water.

(3)

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History of the atom How and why the model of the atom has changed over

time, including:o The plum pudding modelo Rutherford and Marsden’s alpha scattering

experimentso Bohr’s changes to the nuclear modelo Evidence provided by Chadwick

That scientific theories are changed or replaced because of new evidence


Comprehension Task 1. Correct the mistake in each sentence.

a) The plum pudding model is a ball of negative charge with positive protons dotted amongst it.

b) In the gold leaf experiment, Rutherford and Marsden fired negatively charged alpha particles at gold foil. All of the particles passed straight through the foil.

c) This proved the existence of a nucleus which contains all of the mass and most of the positive charge of the atom.

2. Connect each key scientist to the correct atomic model or discovery.

Bohr

Dalton

Chadwick

Rutherford

Discovered that the nucleus contained neutrally charged particles called neutrons.

Determined the existence of specific electron shells.

Proposed the plum pudding model, which was a sphere of positive charge with negative electrons scattered within it.

Discovered that the atom was mostly empty space, with most of the mass concentrated in a central nucleus.

As05 History of the Atom

Q1.This question is about the structure of the atom.

(a) Complete the sentences.

Choose answers from the box.

Each word may be used once, more than once, or not at all.

electron ion neutron

nucleus proton

The centre of the atom is the

The two types of particle in the centre of the atom are the proton

and the

James Chadwick proved the existence of the

Niels Bohr suggested particles orbit the centre of the atom. This type of particle

is the

The two types of particle with the same mass are the neutron

and the

(5)

Q2.The plum pudding model of the atom was replaced by the nuclear model.

The nuclear model was developed after the alpha particle scattering experiment.

Compare the plum pudding model with the nuclear model of the atom.

(4)

Q3.Scientists used alpha particles to investigate models of the atom.

Figure 4 shows an alpha particle scattering experiment.

Figure 4

Explain how scientists used the results from the experiment to:

disprove the plum pudding model give evidence for the new nuclear model.

(4)

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Structure of the atom The location, relative charge and relative mass of protons,

neutrons and electrons What atomic number and mass number represent in an

atomic symbol Why atoms have no charge overall That atoms of an element all have the same number of

protons


Comprehension Task1. Complete the table detailing the relative mass, relative charge and position of the three

subatomic particles.

Subatomic Particle Relative Mass Relative Charge Location in

atom

Proton

No charge

Orbiting nucleus

2. Complete the following:

The Atomic (Proton) Number of an element is equal to

The Relative Atomic Mass of an element is equal to

In an atom, the number of electrons equals the number of

3. Complete the following table. Use your Periodic Table to help you.

ElementRelative Atomic Mass

Atomic Number

Number of Protons

Number of Neutrons

Number of Electrons

He 4 2 2 2 2

H 1 1

Li 7 3 4

12

S

F

As06 Structure of the Atom Exam Question Practise

Q1.This question is about atomic structure.

The figure below represents the structure of a lithium atom.

(a) Name the particle in the atom that has a positive charge.

(1)

(b) Name the particle in the atom that has the smallest mass.

(1)

(c) Complete the sentences.

Choose the answers from the box.

3 4 7 10

The mass number of the lithium atom is

The number of neutrons in the lithium atom is

(2)

Q2.The diagram represents a carbon atom.

(a) Use words from the box to answer the questions.

electron neutron nucleus proton

(i) What is the name of the central part of the atom?

(1)

(ii) What is the name of the particle with no charge?

(1)

(iii) What is the name of the particle with a negative charge?

(1)

(b) Use the diagram above to help you to answer these questions.

(i) Draw a ring around the atomic (proton) number of this carbon atom.

6 12 18

(1)

(ii) Draw a ring around the mass number of this carbon atom.

6 12 18

(1)

(c) A different carbon atom has 6 protons and 8 neutrons.

Draw a ring around the symbol that represents this atom.

(1)

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Electronic structure How electrons are arranged in an atom The electronic structures of the first 20 elements in the

periodic table How to represent electronic structure using diagrams and

numbers


Comprehension Task 1. Fill in the gaps:

Electrons are charged particles that the atom in energy

levels, or shells. The first shell can accommodate up to electrons. The

second shell can accommodate up to electrons. The third shell can

accommodate up to electrons.

Electrons fill the shell the nucleus first.

2. Write in the electron configurations for the following elements.

Lithium 2, 1

Magnesium

Sulphur

Carbon

Helium

Neon

Aluminium

Chlorine

Potassium

Phosphorous

As07 Electronic Structure Exam Question Practise

Q1.There are eight elements in the second row (lithium to neon) of the periodic table.

(a) Figure 1 shows an atom with two energy levels (shells).

(i) Complete Figure 1 to show the electronic structure of a boron atom.

(1)

(ii) What does the central part labelled Z represent in Figure 1?

(1)

(b) The electronic structure of a neon atom shown in Figure 2 is not correct.

Explain what is wrong with the electronic structure shown in Figure 2.

(3)

Q2.

(a) The electronic structure of a sodium atom can be written 2,8,1.Write the electronic structure of a potassium atom in the same way.

(1)

(b) The electronic structure of a sodium atom can also be represented as in the diagram below.

(i) Draw a similar diagram for a fluorine atom.(1)

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8Ions

The definition of an ion How to work out the number of protons, neutrons and

electrons in an ion


Comprehension Task 1. Correct the statements:

a. An atom becomes an ion when it gains or loses protons.

b. When an atom loses electrons it becomes a negatively charged ion.

c. When an atom gains electrons. It becomes a positively charged ion.

2. For the following ions, give the number of protons, neutrons and electrons. Use your Periodic Table to help you:

Ion Atomic Number

Relative Atomic Mass

Number of Protons

Number of Neutrons

Number of Electrons

H+ 1 1 1 0 0

F-

O2-

K+

Mg2+

Br-

As08 Ions Exam Question Practise

Q1.

When sodium reacts with water it forms sodium ions.The diagrams below represent the electron arrangements of some atoms and ions.

Which of the diagrams, A to E, represents the electron arrangement of each of the following?

(i) A sodium atom, Na

(ii) A sodium ion, Na+

(2)

Q2.This question is about magnesium.

(a) (i) The electronic structure of a magnesium atom is shown below.

Use the correct answer from the box to complete each sentence.

electrons neutrons protons shells

The nucleus contains protons and

The particles with the smallest relative mass that move around the nucleus are

called

Atoms of magnesium are neutral because they contain the same number of

electrons and

(3)

(ii) A magnesium atom reacts to produce a magnesium ion.

Which diagram shows a magnesium ion?

Tick ( ) one box.

(1)

Q3.This question is about sodium chloride (common salt) which is an important chemical. Sodium chloride can be made by burning sodium in chlorine gas.

(a) Balance the symbol equation for the reaction of sodium with chlorine.

Na(s) + Cl2(g) → NaCl(s)

(1)

(b) (i) Complete the diagrams below to show the electronic structures of a sodium and a chlorine atom. (Atomic number of sodium = 11 and chlorine = 17.)

(3)

(ii) When sodium reacts with chlorine the sodium atoms are changed into sodium ions (Na+) and the chlorine atoms are changed into chlorine ions (Cl–). Explain how:

1. a sodium atom changes into a sodium ion;

(2)

2. a chlorine atom changes into a chloride ion.

(2)

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9Isotopes

The definition of an isotope How to work out the number of protons, neutrons and

electrons in an isotope represent an atom’s atomic number and mass number


Comprehension Task 1. Correct the statements:

a. An element is a group of atoms that each have the same number of neutrons.

b. Isotopes of elements occur when atoms have different numbers of electrons.

c. The relative atomic mass of an element on the periodic table is always a whole number, as proven by fluorine.

2. Complete the table to determine the number of protons and neutrons of each isotope. Then, identify the element.

Atomic Number

Relative Atomic Mass

Number of Protons

Number of Neutrons Element

1 1 1 0 Hydrogen

1 2

1 3

17 18

17 19

6 13

As09 Isotopes Exam Question Practise

Q1. Chadwick’s experimental work on the atom led to a better understanding of isotopes.

Explain how his work led to this understanding.

(3)

Q2. Element X has two isotopes. Their mass numbers are 69 and 71

The percentage abundance of each isotope is:

• 60% of 69X

• 40% of 71X

Estimate the relative atomic mass of element X.

Tick one box.

< 69.5

Between 69.5 and 70.0



> 70.5

(1)

Q3.This question is about atoms, molecules and nanoparticles.

(a) Different atoms have different numbers of sub-atomic particles.

(i) An oxygen atom can be represented as O

Explain why the mass number of this atom is 16.

You should refer to the numbers of sub-atomic particles in the nucleus of the atom.

(2)

(ii) Explain why C and C are isotopes of carbon.

You should refer to the numbers of sub-atomic particles in the nucleus of each isotope.

(3)

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Development of the periodic table How the periodic table was developed over time, including

the contribution of Mendeleev to the modern periodic table

How testing a prediction can support or disprove a scientific idea


Comprehension Task1. Complete the table, stating whether each statement is true or false, and giving a reason

for each decision.

Statement True / False Reason

Mendeleev did not leave gaps in his Periodic Table

because he knew all of the elements.

Mendeleev rearranged the elements according to

whether they are a solid, liquid or gas at 20C.

Prior to Mendeleev, the elements were arranged in

order of their atomic weight.

2. Complete the following sentences:

Mendeleev left gaps in his Periodic Table because

Mendeleev left gaps in his Periodic Table but

Mendeleev left gaps in his Periodic Table so

As10 Development of the Periodic Table Atoms Question Practise

Q1.This question is about elements and the periodic table.

(a) Use the correct answers from the box to complete the sentences.

atoms atomic weights electrons proton numbers

Newlands’ and Mendeleev’s periodic tables show the elements in order of

their

Following the discovery of protons and ________________, the modern periodic

table shows the elements in order of their ________________

(3)

Q2.In 1866 John Newlands produced an early version of the periodic table.

Part of Newlands’ periodic table is shown below.

Column 1 2 3 4 5 6 7

H Li Be B C N O

F Na Mg Al Si P S

Cl K Ca Cr Ti Mn Fe

Newlands’ periodic table arranged all the known elements into columns in order of their atomic weight.

Newlands was trying to show a pattern by putting the elements into columns.

(a) Iron (Fe) does not fit the pattern in column 7.

Give a reason why.

(1)

(b) In 1869 Dmitri Mendeleev produced his version of the periodic table.

Why did Mendeleev leave gaps for undiscovered elements in his periodic table?

(1)

Q3.In the 1860s scientists were trying to organise elements.Figure 2 shows the table published by John Newlands in 1865.The elements are arranged in order of their atomic weights.

Figure 2

H Li Be B C N O

F Na Mg Al Si P S

Cl K Ca Cr Ti Mn Fe

Co,Ni Cu Zn Y In As Se

Br Rb Sr Ce,La Zr Di,Mo Ro,Ru

Pd Ag Cd U Sn Sb Te

Figure 3 shows the periodic table published by Dmitri Mendeleev in 1869.

Figure 3

Mendeleev’s table became accepted by other scientists whereas Newlands’ table was not.Evaluate Newlands’ and Mendeleev’s tables.You should include:

a comparison of the tables reasons why Mendeleev’s table was more acceptable.

Use Figure 2 and Figure 3 and your own knowledge.

(6)

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Electronic structure and the periodic table How atomic structure links to the periodic table How metals and non-metals differ, including their position

on the periodic table and their electronic structures Why noble gases are unreactive and the trend in their

properties


Comprehension Task 1. Who am I? Determine each element from the clues given. Then, give the electron

configuration of each element. Use the Periodic Table to help you!a. I have a single, full, shell of electrons. Who am I?

Element: Electron configuration:

b. I have three electron shells and am in Group 5 of the Periodic Table. Who am I?


c. I have a full outer shell of electrons and am found in Period 2 on the Periodic Table.

Who am I?


d. I am found in Period 4 of the Periodic Table. In order to form my ion, I lose one

electron from my outer shell. Who am I?


e. I have three electron shells. I am a metal, found to the right-hand side of the

transition elements. Who am I?


2. Correct the mistake in each sentence.a. Metals are found on the left side of the Periodic Table. When forming ions, they gain

electrons to form negative ions.

b. The Period that an element is in tells you how many electrons are in the outer shell of an atom of that element.

As11 Electronic Structure and the Periodic Table Exam Question Practise

Q1.Figure 1 shows an outline of the modern periodic table.

J, L, M, Q and R represent elements in the periodic table.

(a) Which element has four electrons in its outer shell?

Tick (✔) one box.

J L M Q R

(1)

(b) Which two elements in Figure 1 are in the same period?

________________ and ________________

(1)

(c) Which element has three electron shells?

Tick (✔) one box.

J L M Q R

(1)

Q2.

(a) Figure 2 shows the electron arrangements of three different atoms, X, Y and Z.

These atoms are from elements in the second row (lithium to neon) of the periodic table.

Which atom is from an element in Group 3 of the periodic table?

Tick (✔) one box.

Atom X

Atom Y

Atom Z

(1)

(b) Figure 3 shows the electron arrangement of a different atom from an element in the second row of the periodic table.

(i) Give the chemical symbol of this element.

(1)

§(ii) Why is this element unreactive?

(1)

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Group 1 – Alkali metals How the group 1 elements react and behave How the chemical and physical properties of group 1

elements change going down the group


Comprehension Task 1. Complete the following sentences:

a. Going down Group 1, the elements become more reactive because

b. Going down Group 1, the elements become more reactive but

c. Going down Group 1, the elements become more reactive so

2. Correct the following statements:

a. When reacted with water, the Group 1 elements form a metal carbonate which is insoluble in water.

b. When reacted with oxygen, the Group 1 elements forms a metal oxide which is visible as a grey powder on the surface of the metal.

c. The Group 1 elements react slowly with chlorine to form metal chlorides. These dissolve in water to form coloured solutions.

As12 Alkali Metals Exam Question Practise

Q1.A student was investigating the reaction of lithium and water.

She added a few drops of universal indicator to water in a trough and added a piece of lithium.

The word equation for the reaction is:

lithium + water lithium hydroxide + hydrogen

(a) (i) The lithium floated on the water.

State two other observations that the student would see during the reaction.

1.

2.

(2)

(ii) Balance the symbol equation for the reaction of lithium and water.

2 Li(s) + _____ H2O(l) _____ LiOH(aq) + H2(g)

(2)

(iii) Describe a simple test and the result that would show the gas was hydrogen.

(1)

(iv) All Group 1 metals have similar reactions with water.

State why, in terms of electronic structure.

(1)

Q2. The melting points of the elements in Group 1 show a trend.

The table below shows the atomic numbers and melting points of the Group 1 elements.

Element Atomic number Melting point in °C

Lithium 3 181

Sodium 11 98

Potassium 19 63

Rubidium 37 X

Caesium 55 29

(a) Plot the data from the table on the graph below.

(2)

(b) Predict the melting point, X, of rubidium, atomic number 37

Use the graph above.

Melting point = ______________________°C

(1)

As 1

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Group 7 - halogens How the group 7 elements react and behave How the chemical and physical properties of group 7

elements change going down the group, including displacement reactions of the halides


Comprehension Task 1. Complete the following sentences:

Going down Group 7, the elements become less reactive because

Going down Group 7, the elements become less reactive but

Going down Group 7, the elements become less reactive so

2. Complete the zen diagram to show the similarities and differences of the Group 1 elements and the Halogens.

Group 1 Elements Halogens

As13 Group 7 -Halogens Exam Question Practise

Q1.This question is about the halogens (Group 7).

(a) How do the boiling points of the halogens change down the group from fluorine to iodine?

(1)

(b) Sodium bromide is produced by reacting sodium with bromine.

Sodium bromide is an ionic compound.

(i) Write down the symbols of the two ions in sodium bromide.

(1)

(ii) Chlorine reacts with sodium bromide solution to produce bromine and one other product.

Complete the word equation for the reaction.

chlorine + sodium bromide bromine + ______________

(1)

(iii) Why does chlorine displace bromine from sodium bromide?

(1)

(iv) Use the Chemistry Data Sheet to help you to answer this question.

Suggest which halogen could react with sodium chloride solution to produce chlorine.

(1)

Q2.A student mixes solutions of halogens with solutions of their salts.

The table below shows the student’s observations.

Potassium

chloride (colourless)

Potassium bromide

(colourless)

Potassium iodide

(colourless)

Chlorine (colourless) Solution turns

orangeSolution turns

brown

Bromine (orange) No change Solution turns

brown

Iodine (brown) No change No change

Explain how the reactivity of the halogens changes going down Group 7.

Use the results in the table above.

(3)

As 1

4 Explaining trends The trend in reactivity in group 1 and group 7 How electronic structure explains these trends


Comprehension Task Read the following paragraphs about the Group 1 and 7 Elements. Highlight the correct statements in one colour and the incorrect statements in another.

Elements react by gaining or losing electrons. Elements want to reach the stable state of having 6 electrons in the outermost shell, so group 1 elements react by losing two electrons, since they have only 1 electron in their outermost shell. Group 7 elements react by losing an electron to form an outermost ring of 6 electrons.

Group 1 elements get more reactive down the group because with each step down the group the number of electron shells decreases by 1 so the outermost electron is closer to the positively charged nucleus. The further away the outermost negative electron is from the positive nucleus, the weaker the force of magnetic attraction between the two is and the easier it is for the element to react as less energy is required to remove the electron. Group 7 elements are more reactive down the group because the electron shells attract the reacting electron towards the nucleus, which weakens the force of electrostatic attraction between it and the positive nucleus.

Now, rewrite the paragraphs, correcting any mistakes that you have identified.

As14 Explaining Trends Exam Question Practise

Q1.

(a) The electronic structure of a potassium atom is 2, 8, 8, 1

(i) Draw a diagram to show the electronic structure of a potassium ion.

Show the charge on the potassium ion.

(2)

(ii) Potassium is more reactive than sodium.

Explain why, in terms of electronic structure.

(3)

Q2.This question is about Group 7 elements.

Chlorine is more reactive than iodine.

(a) Name the products formed when chlorine solution reacts with potassium iodide solution.

(1)

(b) Explain why chlorine is more reactive than iodine.

(3)

(c) Explain, in terms of electronic structure why bromine is less reactive than chlorine.

(3)

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The transition elements The properties of the transition elements How the properties of transition elements compare with

the alkali metals


Comprehension Task 1. Complete the zen diagram to show the similarities and differences of the transition

metals and group 1 & 2 metals.

Transition Metals Group 1 Metals

2. Correct the mistake in each statement:

The transition elements are useful as catalysts and form colourless compounds.

Each of the transition elements form ions with the same charge. Iron, for example, can only form ions with a 2+ charge.

The transition metals are found on the left side of the Periodic Table.

As15 The Transition Elements Exam Question Practise

Q1.Transition elements and their compounds have many uses.

Iron oxide and cobalt oxide have been added to the glazes on pottery for hundreds of years.

(a) State why transition metal oxides are added to pottery glazes.

(1)

(b) Use the table of ions on the Data Sheet to help you work out the formula of iron(III) oxide.

(1)

(c) Cobalt oxide is reacted with hydrogen to form cobalt.

(i) Balance the equation for this reaction.

(1)

(ii) Cobalt is mixed with other transition metals to make alloys.

These alloys are used to make cutting tools which remain sharp at very high temperatures. They can cut through other metals.

Suggest two properties of transition metals that make them suitable for making cutting tools.

1.

2.

(2)

Q2. 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.

Transition elements Group 1 elements

Chromium Iron Sodium Caesium

Melting pointin °C

1857 1535 98 29

Formula ofoxides

CrO FeO Na2O Cs2O

Cr2O3 Fe2O3

CrO2 Fe3O4

CrO3

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)

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