Structure and Bonding

Transcription

1 Structure and Bonding Foundation revision questions Name: Class: Date: Time: 66 minutes Marks: 65 marks Comments: Page of 25

2 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? () What is the name of the particle with no charge? () (iii) What is the name of the particle with a negative charge? () (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 () Draw a ring around the mass number of this carbon atom () Page 2 of 25

3 (c) A different carbon atom has 6 protons and 8 neutrons. Draw a ring around the symbol that represents this atom. () (d) The diagram shows the bonding in a methane molecule. (i) Draw a ring around the chemical formula of a methane molecule. CH 4 CH 4 C 4 H () Draw a ring around the word that describes methane. compound element mixture () (iii) Draw a ring around the type of bonding in a methane molecule. covalent ionic metallic () (Total 9 marks) Page 3 of 25

4 2 This question is about different substances and their structures. (a) Draw one line from each statement to the diagram which shows the structure. Statement Structure (4) Page 4 of 25

5 (b) Figure shows the structure of an element. Figure What is the name of this element? Tick one box. Carbon Chloride Nitrogen Xenon () (c) Why does this element conduct electricity? Tick one box. It has delocalised electrons It contains hexagonal rings It has weak forces between the layers It has ionic bonds () Page 5 of 25

6 (d) Figure 2 shows the structure of an alloy. Figure 2 Explain why this alloy is harder than the pure metal Y (2) (e) What percentage of the atoms in the alloys are atoms of X? (2) (f) What type of substance is an alloy? Tick one box. Compound Element Mixture () (Total marks) Page 6 of 25

7 3 The picture shows a student filling in a multiple choice answer sheet using a pencil. Cihan Ta?k?n/iStock The pencil contains graphite. Graphite rubs off the pencil onto the paper. Diagrams and 2 show how the atoms are arranged in graphite. (a) Use the diagrams to help you explain why graphite can rub off the pencil onto the paper. (2) (b) Draw a ring around the type of bond which holds the atoms together in each layer. covalent ionic metallic () (Total 3 marks) Page 7 of 25

8 4 The diagrams represent the structures of five substances, A, B, C, D and E. (a) Give one substance, A, B, C, D or E, that: (i) has a very low boiling point () is a compound () (iii) is a metal. () Page 8 of 25

9 (b) Draw a ring around the type of bonding holding the atoms together in substance C. covalent ionic metallic () (c) Explain why substance E is soft and slippery. (2) (Total 6 marks) 5 This question is about substances containing carbon atoms. (a) Diamond is made of carbon atoms. (i) Diamond is used for tips of drills. Figure shows a drill. Kershawj/iStock Give one reason why diamond is used for tips of drills () Diamond nanoparticles can be made. Use the correct answer from the box to complete the sentence. hundred million thousand Nanoparticles contain a few... atoms. () Page 9 of 25

10 (b) Graphite is made of carbon atoms. Figure 2 shows the structure of graphite. (i) What type of bonding does graphite have? Tick ( ) one box. Covalent Ionic Metallic () How many carbon atoms does each carbon atom bond to in graphite? Tick ( ) one box () Page 0 of 25

11 (iii) What is a property of graphite? Tick ( ) one box. Dissolves in water Has a low melting point Soft and slippery () (c) Poly(ethene) is made of carbon and hydrogen atoms. Poly(ethene) is a thermosoftening polymer. Figure 3 shows the structure of a thermosoftening polymer. (i) Complete the sentence. Between the polymer chains in a thermosoftening polymer there are no.... () Use the correct answer from the box to complete the sentence. condense dissolve melt Heating would cause a thermosoftening polymer to.... () Page of 25

12 (iii) Many ethene molecules react together to make poly(ethene). Different types of poly(ethene) can be made by changing the conditions for the reaction. Suggest two conditions that could be changed.. 2. (2) (d) Figure 4 shows how the atoms are bonded in methane. (i) What is the formula for methane? Tick ( ) one box. C 4 H CH 4 C 4 H 4 () Page 2 of 25

13 Methane has a low boiling point. What does methane consist of? Tick ( ) one box. Charged ions A giant lattice Small molecules () (Total marks) 6 The diagram represents a magnesium atom. (a) Use words from the box to answer these questions. electron neutron nucleus proton (i) What is the name of the central part of the atom?... What is the name of the particle with no charge?... (iii) What is the name of the particle with a negative charge?... () () () (b) Use the diagram above to help you answer these questions. (i) Draw a ring around the atomic (proton) number of this magnesium atom () Page 3 of 25

14 Draw a ring around the mass number of this magnesium atom () (c) The diagram shows how magnesium and iodine atoms form magnesium iodide. Only the outer electrons are shown. The dots ( ) and crosses ( ) are used to represent electrons. Use the diagram to help you to answer this question. Describe, as fully as you can, what happens when magnesium reacts with iodine to make magnesium iodide. To gain full marks you should use the words atom, electron and ion in your answer. (4) (Total 9 marks) Page 4 of 25

15 7 The structures of four substances, A, B, C and D, are represented in Figure. (a) Use the correct letter, A, B, C or D, to answer each question. (i) Which substance is a gas? () Which substance is a liquid? () (iii) Which substance is an element? () (iv) Which substance is made of ions? () Page 5 of 25

16 (b) Figure 2 shows the bonding in substance C. (i) What is the formula of substance C? Draw a ring around the correct answer. SO 2 SO 2 S 2 O () Use the correct answer from the box to complete the sentence. delocalised shared transferred When a sulfur atom and an oxygen atom bond to produce substance C, electrons are... () (iii) What is the type of bonding in substance C? Draw a ring around the correct answer. covalent ionic metallic () (Total 7 marks) Page 6 of 25

17 8 Kelp is a seaweed. Kelp can be burned to give out energy. Ethan Daniels/Shutterstock (a) Draw a ring around the correct answer to complete each sentence. endothermic. Reactions which give out energy are exothermic. reversible. () (b) Which two of the following questions cannot be answered by scientific experiments alone? Tick ( ) two boxes. Question Tick ( ) How much carbon dioxide is produced when 00 g of kelp is burned? Does kelp give out more heat energy than coal when burned? Should people use kelp instead of oil as an energy source? Will kelp be more popular than coal in the next 0 years? (2) Page 7 of 25

18 (c) Potassium iodide can be produced from kelp. (i) Potassium can be reacted with iodine to produce potassium iodide. potassium + iodine potassium iodide The diagram shows how this happens. Only the outer electrons are shown. The dots ( ) and crosses ( ) are used to represent electrons Use the diagram to help you answer this question. Describe, as fully as you can, what happens when potassium reacts with iodine to produce potassium iodide. To get full marks you should use the words atom, electron and ion in your answer. (4) Potassium iodide reacts with lead nitrate. 2 KI(aq) + Pb(NO 3 ) 2 (aq) 2 KNO 3 (aq) + PbI 2 (s) Why is this reaction a precipitation? () Page 8 of 25

19 (iii) How can the precipitate be removed from the reaction mixture? () (Total 9 marks) Page 9 of 25

20 Mark schemes (a) (i) nucleus (iii) neutron electron (b) (i) 6 2 (c) (d) (i) CH 4 compound (iii) covalent [9] Page 20 of 25

21 2 (a) Statement Structure (b) (c) (d) more than one line drawn from a variable negates the mark Carbon It has delocalised electrons the atoms / particles / ions are different sizes do not accept molecules so there are no rows / layers to slide accept the layers are disrupted 4 (e) 7.4% allow 7.4% with no working shown for 2 marks (f) Mixture [] Page 2 of 25

22 3 (a) layers which have weak forces / attractions / bonds between them second mark must be linked to layers or which can slide over each other or separate ignore references to rubbing (b) covalent [3] 4 (a) (i) C (iii) C or D A (b) (c) covalent layers can slide / move over each other accept are weakly bonded (owtte) allow no bonds between layers ignore slip / rub [6] 5 (a) (i) hard ignore strong hundred (b) (i) Covalent 3 (iii) Soft and slippery Page 22 of 25

23 (c) (i) cross-links allow bonds ignore links do not accept intermolecular (iii) melt any two from: temperature allow heat(ing) pressure catalyst 2 (d) (i) CH 4 Small molecules [] 6 (a) (i) nucleus (iii) neutron electron (b) (i) 2 24 Page 23 of 25

24 (c) any four from: sharing / covalent / metallic = max 3 magnesium (atom) reacts with two iodine (atoms) magnesium (atom) loses electrons 2 electrons (from each atom) Iodine (atom) gains electron(s) electron or an electron (to each atom) iodide ion formed allow iodine ion iodide has negative charge / is a negative ion / particle allow iodine ignore I 2 magnesium ion formed magnesium has positive charge oppositely charged ions attract a giant structure / lattice is formed allow mark for unqualified reference to ion formation or ionic bonding 4 [9] 7 (a) (i) C (iii) (iv) B A D (b) (i) SO 2 shared (iii) covalent [7] 8 (a) exothermic Page 24 of 25

25 (b) Should people use kelp instead of oil as an energy source? Will kelp be more popular than coal in the next 0 years? (c) (i) any four from: If atom or ion omitted = max 3 sharing / covalent / metallic = max 3 ignore reference to full outer shells potassium (atom) loses (an electron) and iodine (atom) gains (an electron) electron iodide (ion) has negative charge allow iodine ion potassium (ion) has positive charge electrostatic attraction or ionic bonding accept stable (structure) or noble gas (structure) 4 because a solid is formed (from two aqueous solutions) (iii) filtering or centrifuging or decanting [9] Page 25 of 25