| Method |
Precise Learning Objective |
Linked |
Question / Activity
(Designed for maximum working out) |
Stepping Stones |
Pitstop Check
(Thinking Map) |
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The elements in Group 7 of the periodic table are known as the halogens and have similar reactions because they all have seven electrons in their outer shell. |
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What is the common name given to the group 7 elements? |
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The halogens are non-metals and consist of molecules made of pairs of atoms. |
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Students should be able to describe the nature of the compounds formed when chlorine, bromine and iodine react with metals and non-metals. |
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In Group 7, the further down the group an element is the higher its relative molecular mass, melting point and boiling point. |
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Describe the trend in boiling point and melting point of elements as you go down group 7? Draw / sketch a graph to show the melting and boiling points of group 7 elements |
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In Group 7, the reactivity of the elements decreases going down the group. |
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Describe the trend in reactivity of elements as you go down group 7? DEMO Displacement reactions - http://www.rsc.org/learn-chemistry/resource/res00000733/reactions-of-halogens-as-aqueous-solutions?cmpid=CMP00006118
Model the decreases size of atoms down group 7 using fluffy balls and rings drawn on tables or students draw configurations in their books to deduce why the reactivity decreases.
EW: Describe and explain why the reactivity of group 7 metals decreases as you go down the group. |
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A more reactive halogen can displace a less reactive halogen from an aqueous solution of its salt. |
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Write a word equation for the reaction between sodium chloride and fluorine. What type of reaction is this? Model displacement reactions with students or using famous people for "attraction" factors |
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Students should be able to explain how properties of the elements in Group 7 depend on the outer shell of electrons of the atoms |
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In terms of electron structure, whAt do all group 7 elements share in common? |
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Students should be able to predict properties from given trends down the group. |
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List the elements of group 7 in order of reactivity. |
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Many transition elements have ions with different charges, form coloured compounds and are useful as catalysts. |
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Many transition elements are also useful as catalysts. What is a catalyst? Demo:
Place a 250 cm3 conical flask on a heat resistant mat. Add acetone to the flask to a depth of 5 mm (approximately 30 cm3 of acetone). Trim a sheet of copper foil and bend it to hook over a glass rod. Check that when the copper foil is lowered into the flask it is held approximately 2 cm above the base.
Heat the copper directly until it is red hot, then lower it into the conical flask. Waves of colour will ripple across its surface as it catalyses the oxidation of the acetone. The effect is emphasised if the lights are turned off and the copper will continue to glow as long as there is a supply of acetone vapour.
http://www.rsc.org/learn-chemistry/resource/res00001235/catalytic-copper |
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Students should be able to exemplify these general properties by reference to compounds of Cr, Mn, Fe, Co, Ni, Cu. |
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List the general properties of compounds of transition elements |
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