1. 1
   A technician reacts samples of the halogens fluorine, chlorine, bromine and iodine with sodium metal to form the corresponding sodium halides, and records the melting and boiling points of the four halogens used.

   (a)

   What is the charge on a halide ion formed when a Group 7 element reacts with a metal?

   [1 mark]

   • A-1
   • B+1
   • C-2
   • D+2

   (b)

   Which type of bonding is present in the sodium halide compounds formed in these reactions?

   [1 mark]

   • ACovalent bonding
   • BIonic bonding
   • CMetallic bonding
   • DNo bonding, a mixture

   (c)

   Describe the trend in melting and boiling points of the halogens that the technician would record, going from fluorine to iodine.

   [2 marks]

   Total for question 1: 4 marks

2. 2
   A student is given four sealed tubes, each containing one of the halogens fluorine, chlorine, bromine or iodine, and observes the physical state of each substance at room temperature.

   (a)

   At room temperature, what physical state is chlorine, near the top of Group 7?

   [1 mark]

   • ASolid
   • BLiquid
   • CGas
   • DPlasma

   (b)

   Compared with chlorine, how reactive is iodine, which is further down Group 7?

   [1 mark]

   • AIodine does not react at all
   • BMore reactive
   • CExactly the same reactivity
   • DLess reactive

   (c)

   Bromine is found to be a liquid at room temperature, between chlorine (a gas) and iodine (a solid). Explain what this tells the student about the general trend in melting and boiling points down Group 7.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   A group of students compares samples of chlorine, bromine and iodine, each reacted separately with iron wool, and records how vigorously each halogen reacts.

   (a)

   State the general trend in reactivity of the halogens going down Group 7, and identify which of chlorine, bromine and iodine is the most reactive.

   [3 marks]

   (b)

   When chlorine gas is passed over hot iron wool, an ionic compound is formed. Describe the type of ion formed by chlorine in this reaction and describe the general properties of the ionic compound produced.

   [4 marks]

   Total for question 3: 7 marks

4. 4
   A teacher demonstrates the reactions of the halogens with metals and reviews the physical properties of fluorine, chlorine, bromine and iodine with the class, before setting an extended question on the trends observed across the whole group.

   (a)

   Describe fully the trends seen going down Group 7 of the periodic table in terms of physical state, melting point, boiling point and reactivity, and explain what type of ion the halogens form when reacting with metals.

   [6 marks]

   (b)

   A new, undiscovered halogen is proposed to exist directly below iodine in Group 7. Using the trends across Group 7, predict and justify the physical state, relative reactivity, and the charge on the ion it would form with a metal.

   [6 marks]

   Total for question 4: 12 marks

End of questions