Elements, Compounds and MixturesYear 8 Science 2021

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Name: _____________________________

Student OutcomesTo understand that:• Substances can be pure elements, compounds or mixtures which are allcomposed of atoms• Specific atoms that make up a substance and how they are arranged determine the properties of the substance• The atomic model and particle theory are simplified models that help us to explain the observed properties of substances• Scientific models continue to develop and change over time as new scientificevidence is found

To know that:• Elements are made up of single types of atoms• Compounds are composed of different elements.

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• Substances can form as a result of molecules, single atoms or lattices ofatoms• The periodic table arranges the elements in such a way that their propertiescan be predicted• At the atomic level the number of protons determines the identity of theelement.

To be able to:• Identify and write correct formulas for elements and compounds following standard conventions• Relate the structure of a substance to its properties.• Carry out experiments to model the structure of substances and investigate the changes in properties observed when compounds are formed from individual elements.

AssessmentTest (100%)

Metals and Non-MetalsQ1. On the periodic table below, highlight the metals in one colour and the non-metals in another. You are also required to highlight the metalloids in a third colour 

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 Q2. Identify the elements from the word bank as metals or non-metals. Write them in the table below. * hint * use the element position of the periodic table to assist with your answers manganese - S - chlorine - Cu - Al - iodine - Na - argon -

carbon - Zn - boron - Kiron - O - helium - silicon - Ag - Cr - fluorine - Au - Mg -

hydrogen 

Metals Non-Metals Metalloid   

Q3. Highlight the element that is the odd one out in each group. Give a reason for your answer.(a) magnesium, silver, bromine, nickel

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(b) Ca, Ba, Ni, Mg

(c) Kr, Cu, Zn, Ag

 

(d) oxygen, helium, nitrogen, sodium  

Q4. (a) Define the term “alloy”________________________________________________________________________________________________________________________________(b) List the two elements found in steel ________________________________________________________________

Q5. Based on the properties shown, classify each of the elements P, Q, R and S as a metal or non-metal

Element Melting point (°C)

Boiling point (°C)

Conductivity

Metal/Non-metal

P 1490 2900 GoodQ -7 58 PoorR 1540 3000 GoodS 114 183 Poor

 Q6. Match the definition to the term

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Conductors of

electricity

Able to transfer electricity through substance

Conductors of heat Able to transfer heat through substance

Ductile Can be made into a wire

Brittle Hard but can break into many pieces

Dull Not shiny in appearance but can be colourful

High melting

and boiling points

High temperature required to change substance from a solid to a liquid (melting) or liquid to gas (boiling)

Malleable Can be shaped by a hammer

Lustrous Shiny in appearance

Q7. Use the terms above to contrast/compare the properties of metallic and non-metallic elements.

Metals Non-Metals 

EXTENSTION: Metallic bonding (Additional PowerPoint and Worksheet)6

Element Fact FileElement: _______________________________________Physical and Chemical Properties

ColourOdorState of matter at room temperatureTextureDensityFlammabilityMelting pointBoiling pointHow reactive is it?

Periodic Table InformationMetal or Non-metalAtomic numberAtomic massPeriodGroupName the family to which it belongs to

Interesting FactsWho discovered your element?When was it discovered? How is your element sourced?

List some common uses of your element

Other interesting

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facts …Particle TheoryQ1. Describe the characteristics of a solid, liquid and gas Solid  

 

Liquid  

 Gas 

  Q2. Draw the arrangement of particles in each state of matter below

 Q3. The melting point and boiling point of a substance helps us determine which state of matter it is in at a certain temperature. Use the data in the table below to answer the following questions. 

Substance Melting Point (°C)

Boiling Point (°C)

Water 0 100Copper 1084 2562Sodium 801 1413

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ChlorideCarbon Dioxide

-78.5 -56

Mercury -39 357Hydrogen -259 -252

 (a) Which substance has the lowest melting point?  (b) Which substance has the highest boiling point?  (c) At 25°C what state of matter is carbon dioxide?   (d) At 100°C what state of matter is mercury?   

(e) At 2000°C what state of matter is sodium chloride?   (f) At 2000°C what state of matter is copper?   (g) At -300°C what state of matter is hydrogen?   (h) At -60°C what state of matter is carbon dioxide?  (i) At -20°C what state of matter is water?  (j) For copper to become a gas, what is the minimum temperature it must become? 

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 (k) What temperature does hydrogen have to be, before it will change for a gas to a liquid? 

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The Periodic Table1H1.0

hydrogen

2He4.0

helium

3Li6.9

lithium

4Be9.0

beryllium

atomic number

relative atomic mass

79Au

197.0gold

symbol of element

name of element

5B

10.8boron

6C

12.0carbon

7N

14.0nitrogen

8O

16.0oxygen

9F

19.0fluorine

10Ne

20.2neon

11 12 13 14 15 16 17 18Na Mg Al Si P S Cl Ar

23.0 24.3 27.0 28.1 31.0 32.1 35.5 39.9sodium magnesium aluminium silicon phosphorus sulfur chlorine argon

19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr

39.1 40.1 45.0 47.9 50.9 52.0 54.9 55.8 58.9 58.7 63.5 65.4 69.7 72.6 74.9 79.0 79.9 83.8potassium calcium scandium titanium vanadium chromium manganese iron cobalt nickel copper zinc gallium germanium arsenic selenium bromine krypton

37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe85.5 87.6 88.9 91.2 92.9 96.0 (98) 101.1 102.9 106.4 107.9 112.4 114.8 118.7 121.8 127.6 126.9 131.3

rubidium strontium yttrium zirconium niobium molybdenum technetium ruthenium rhodium palladium silver cadmium indium tin antimony tellurium iodine xenon

55 56 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86Cs Ba 57–71 Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn

132.9 137.3 lanthanoids 178.5 180.9 183.8 186.2 190.2 192.2 195.1 197.0 200.6 204.4 207.2 209.0 (210) (210) (222)caesium barium hafnium tantalum tungsten rhenium osmium iridium platinum gold mercury thallium lead bismuth polonium astatine radon

87 88 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118Fr Ra 89–103 Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og

(223) (226) actinoids (261) (262) (266) (264) (267) (268) (271) (272) (285) (280) (289) (289) (292) (294) (294)francium radium rutherfordium dubnium seaborgium bohrium hassium meitnerium darmstadtium roentgenium copernicium nihonium flerovium moscovium livermorium tennessine oganesson

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57 58 59 60 61 62 63 64 65 66 67 68 69 70 71La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu

138.9 140.1 140.9 144.2 (145) 150.4 152.0 157.3 158.9 162.5 164.9 167.3 168.9 173.1 175.0lanthanum cerium praseodymium neodymium promethium samarium europium gadolinium terbium dysprosium holmium erbium thulium ytterbium lutetium

89 90 91 92 93 94 95 96 97 98 99 100 101 102 103Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr

(227) 232.0 231.0 238.0 (237) (244) (243) (247) (247) (251) (252) (257) (258) (259) (262)actinium thorium protactinium uranium neptunium plutonium americium curium berkelium californium einsteinium fermium mendelevium nobelium lawrencium

The Periodic TableQ1. Label the following using the words below: Atomic Number - Mass Number - Symbol – Element

  Q2. Define the following terms:

(a) Group: _____________________________________________________

(b) Period: _____________________________________________________

Q2. State which element is located in 

(a) period 2, group 1   (b) period 2, group 16   (c) period 3, group 17   (d) period 5, group 2 

(e) period 4, group 1812

 Q3. State the period and group of the following elements:

(a) Silver  (b) Carbon  (c) Helium  

Q4. State which atom has an atomic mass of:  (a) 12.0

  (b) 40.1  (c) 107.9  

Q5. State which atom has an atomic number of: 

(a) 9  

(b) 26   (c) 79  

Q6. What are the names of the following elements?

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Structure of an AtomQ1. Write a definition for the following words:

(a) Electron: ______________________________________________________________________________________________________________

(b) Proton: ________________________________________________________________________________________________________________

(c) Neutron: ______________________________________________________________________________________________________________

(d) Atomic Number: ________________________________________________________________________________________________________

(e) Mass Number: __________________________________________________________________________________________________________

Q2. Draw a labelled atom for the following elements using the labels: protons, neutrons, electrons. You must calculate how many protons, neutrons and electrons are in each atom and draw these in your diagram. Remember, the first shell holds 2 electrons, the second and third shell holds 8 electrons.

Helium Boron Sodium

Carbon Chlorine Aluminium

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Q3. Write the electron configuration for the following elements:(a) Beryllium  (b) Magnesium  (c) Sulphur  

Q4. Use the Periodic Table to help you fill in the following table for the following elements

Element Symbol

Atomic number

Mass numbe

r

Number of

neutrons

Number of

protons

Number of

electrons

    1        

    2        

    4        

    11        

    20        

    26        

    30        

    13        

    7        

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    35        

EXTENSTION: Electron configurations (additional worksheet)Molecules and CompoundsQ1. Draw a line to match the following definitions  

Term   DefinitionMolecule   a substance that contains two or more

of the same atoms bonded togetherCompound 

  a substance that contains a single atom

Molecular Element 

  a substance that contains only two atoms

Molecular Compound 

  a substance made up of two or more different types of atoms bonded together

Monoatomic 

  a group of two or more atoms bonded together

Diatomic  

  a substance that contain two or moredifferent atoms bonded together

 Q2. Identify the following substances as an element, molecular compound or molecular element

      

      

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 Q3. Identify the following substances as an element, molecular compound or molecular element

CH4  NaCl  K  Cu  Ca  C2H4  Cl2  CuSO4  F2  

 Counting AtomsQ4. Fill in the table below

Substance Types of atoms Total number of atoms

Water

2 hydrogen atoms

1 oxygen atom

3 atoms in total

Hydrochloric acid(HCl)

1 hydrogen atom

1 chlorine atom

2 atoms in total

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Carbon Dioxide

   

Substance Types of atoms Total number of atoms

Sulphuric acidH2SO4

   

 

Hydrogen peroxide

   

 

GlucoseC6H12O6

   

 

Carbon monoxide

   

CaffeineC8H10N4O2

   

 

Ammonia

   

 

Copper SulphateCuSO4

 

   

 

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EXTENSTION: Writing chemical formula (additional worksheet)Elements, Compounds and MixturesQ1. Decide whether each of the following diagrams represents an element, a compound, or a mixture, and explain your reasons.

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This diagram shows particles in a_________________________________I think this because …

This diagram shows particles in a_________________________________I think this because …

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This diagram shows particles in a_________________________________I think this because …

This diagram shows particles in a_________________________________I think this because …

This diagram shows particles in a_________________________________I think this because …

This diagram shows particles in a_________________________________I think this because …

Practical Investigations21

This diagram shows particles in a_________________________________I think this because …

Metals and Non-metals PracticalAim: To investigate the properties of various elements and to determine which are metals and which are non-metals.

Materials:• Samples of metals and

non-metals• Sandpaper• Power pack• Connecting wires with

crocodile clips

• Light bulb in holder• Nichrome wire holder• 100 mL beaker• Bunsen Burner• Bench mat

Method:PART A – Investigating properties of Metals and Non-metals

1. Rub each of the samples with sandpaper and observe whether they are shiny or dull.

2. Try to bend each sample using fingers. If it can be bent, it is malleable. If it breaks into pieces, it is brittle.

3. Connect the circuit to determine whether or not the samples conduct electricity.

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PART B – Flame Test1. Place the nichrome wire into a small sample of one of the metal

chlorides2. Hold the wire in the outside of the Bunsen flame and observe the

colour of the flame.3. Record your observations. 4. Repeat steps 1-3 to test each of the other samples.

Results:PART A – Investigating properties of Metals and Non-metals

Sample(Element)

Lustre(Shiny or dull?)

Malleability(Does it bend or

is it brittle?)

Electrical conductivity(Yes or No?)

PART B – Flame TestSample Flame Colour Metal

1234567

Discussion:1. List the characteristics you would expect to find in metals and non-

metalsMetals Non-Metals

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2. Based on your observations, which of these elements are metals and which are non-metals?

Metals Non-Metals

EXTENSION3. Explain why light is emitted during a flame test.

________________________________________________________________________________________________________________________________________________________________________________________________________________________

Conclusion:Write a statement summarising your findings in this experiment. Be sure that it relates back to the aim._________________________________________________________________________________________________________________________________________________________________________________________________________________________________Murder at the Manor Activity

Mr Sodium exploded and three of the other guests have disappeared at the Periodic Manor House. A light was smashed just before the murder occurred and caused all the lights to go

out so nobody saw what happened!Can you find out what happened?

Each student is assigned a card with their element's properties and something thatthey saw just before or just after the murder. Some facts are directly related, otherfacts are non-related, but which is which? You will need to cross reference and record the information. Your task is to write an investigator report detailing what happened and how it happened.

____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

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___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________Let’s Collect an Element PracticalAim: To make and collect the element hydrogen (H2) and to discover some of its properties/characteristics

Materials:• Safety glasses• Test tubes (x2)• Test tube rack• Rubber stopper

• Dilute hydrochloric acid (HCl)

• Magnesium (Mg) metal• Matches • Stopwatch

Method:1. Add about 2 cm of hydrochloric acid to the test tube.2. Add the piece of magnesium metal to the acid and immediately

place the rubber stopper inside the mouth of the test tube. 3. Hold the rubber stopper down with your thumb. Start the stopwatch.4. Carefully observe what happens and record your observations in the

table.5. After one minute, light a match and place it near the test tube.

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6. Remove the rubber stopper and immediately place the flame of the match over the mouth of the test tube. Record your observations.

Results: Describe what happened in the test tube containing the magnesium and acid

Describe the appearance of the hydrogen collected

Describe what happened when the hydrogen gas was lit

Describe what you see inside the test tube after the hydrogen was lit

Discussion: 1. Identify magnesium, hydrogen gas, and hydrochloric acid as an

element, molecule, compound, lattice. Note that there can be more than one answer

Substance Structure ExplainMagnesium (Mg)

Hydrogen gas (H2)

Hydrochloric acid (HCl)

2. Draw a labelled diagram of an atom for Magnesium and Hydrogen

Magnesium Hydrogen

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3. Based on your observations in this experiment, state two properties/characteristics you observed about:(a)Magnesium -

_________________________________________________________________________________________________________________________

(b)Hydrogen gas - _______________________________________________________________________________________________________________________

4. Why do you think it was important to keep the rubber stopper in place before lighting the gas?_____________________________________________________________________

EXTENSION5. Write a worded equation showing the reaction between magnesium

and hydrochloric acid _____________________________________________________________________

6. Write a chemical equation showing the reaction between magnesium and hydrochloric acid _____________________________________________________________________

Conclusion:_________________________________________________________________________________________________________________________________________________________________________________________________________________________________

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