Simple molecules and covalent bonds — Paper 1 · IGCSE Sciences - Co-ordinated (Double) 0654

14 The element phosphorus burns in air, as shown. 4P + 5O2 → P4O10 What does the formula P4O10 show? A a mixture of atoms of two elements B a mixture of molecules of two elements C a molecule of a compound D an atom of a compound

1 marks

Answer: C

This question in 0654/11 May/June 2009

14 Element X can form four covalent bonds. Element Y can form two covalent bonds. What is the simplest formula of the compound formed by X and Y? A XY2 B X2Y C X2Y4 D X4Y2

1 marks

Answer: A

This question in 0654/11 Oct/Nov 2009

15 The diagram shows a circuit. Solid X makes the lamp light. X What is solid X? A rubber B silicon(IV) oxide C sulfur D zinc

1 marks

Answer: D

This question in 0654/11 Oct/Nov 2010

28 Elements X and Y react together to form a compound. The diagram shows the outer shells of X and Y after reaction. X electron Y electron outer shell of X outer shell of Y after reaction after reaction Which statement is correct? A X is in group VII and has formed the X+ ion. B X is in group VII and has formed the X– ion. C X is in group VIII and has formed the X+ ion. D X is in group VIII and has formed the X– ion.

1 marks

Answer: B

This question in 0654/13 Oct/Nov 2010

18 Some properties of three substances are shown. melting point boiling point electrical conductivity substance / °C / °C when molten W 801 1413 good X −111 −78 poor Y 1610 2230 poor What are the structures of W, X and Y? giant covalent giant ionic molecular structure structure structure A W Y X B X W Y C Y W X D Y X W

1 marks

Answer: C

This question in 0654/11 May/June 2011

17 Some properties of three substances are shown. melting point boiling point electrical conductivity substance / °C / °C when molten W 801 1413 good X −111 −78 poor Y 1610 2230 poor What are the structures of W, X and Y? giant covalent giant ionic molecular structure structure structure A W Y X B X W Y C Y W X D Y X W

1 marks

Answer: C

This question in 0654/12 May/June 2011

17 Some properties of three substances are shown. melting point boiling point electrical conductivity substance / °C / °C when molten W 801 1413 good X −111 −78 poor Y 1610 2230 poor What are the structures of W, X and Y? giant covalent giant ionic molecular structure structure structure A W Y X B X W Y C Y W X D Y X W

1 marks

Answer: C

This question in 0654/13 May/June 2011

27 The positions of four elements are shown in part of the Periodic Table. W X Y Z Which elements form a bond by sharing electrons? A W and X B W and Y C X and Y D Y and Z

1 marks

Answer: C

This question in 0654/11 Oct/Nov 2011

25 The positions of four elements are shown in part of the Periodic Table. W X Y Z Which elements form a bond by sharing electrons? A W and X B W and Y C X and Y D Y and Z

1 marks

Answer: C

This question in 0654/12 Oct/Nov 2011

26 The positions of four elements are shown in part of the Periodic Table. W X Y Z Which elements form a bond by sharing electrons? A W and X B W and Y C X and Y D Y and Z

1 marks

Answer: C

This question in 0654/13 Oct/Nov 2011

15 A model of a molecule is shown. key hydrogen atom boron atom Which row shows the formula and describes the bonding in this molecule? formula bonding A 2BH3 covalent B 2BH3 ionic C B2H6 covalent D B2H6 ionic

1 marks

Answer: C

This question in 0654/12 May/June 2013

19 Hydrogen can occur as an atom, an ion and a molecule. Which row represents these particles? atom ion molecule A H H+ H2 B H H2 H+ C H+ H H2 D H2 H+ H

1 marks

Answer: A

This question in 0654/11 Oct/Nov 2013

16 The diagram shows the electronic structures of carbon and hydrogen atoms. C H What is the formula of the simplest compound formed between carbon and hydrogen? A CH2 B CH4 C C2H D C4H

1 marks

Answer: B

This question in 0654/11 May/June 2014

15 Which row identifies the types of elements that form covalent compounds and the physical properties of covalent compounds? types of elements physical property A metals and non-metals high volatility B metals and non-metals low volatility C non-metals only high volatility D non-metals only low volatility

1 marks

Answer: C

This question in 0654/12 May/June 2014

15 The diagram shows the electronic structures of carbon and hydrogen atoms. C H What is the formula of the simplest compound formed between carbon and hydrogen? A CH2 B CH4 C C2H D C4H

1 marks

Answer: B

This question in 0654/13 May/June 2014

17 Diagrams 1, 2, 3 and 4 represent atoms and molecules. 1 2 3 4 Which statement is correct? A 1, 2 and 3 are molecules and 4 is an atom. B 1, 2 and 4 are molecules and 3 is an atom. C 1, 3 and 4 are molecules and 2 is an atom. D 2, 3 and 4 are molecules and 1 is an atom.

1 marks

Answer: B

This question in 0654/13 Oct/Nov 2014

19 Some properties of three substances are shown. melting point boiling point electrical conductivity substance / °C / °C when solid W 801 1413 poor X −111 −78 poor Y 1610 2230 good What are W, X and Y? metallic ionic covalent A W Y X B X W Y C Y W X D Y X W

1 marks

Answer: C

This question in 0654/13 Oct/Nov 2014

14 W, X, Y and Z are diagrams of atoms and molecules. W X Y Z Which statement is correct? A W and Z are molecules and X and Y are atoms. B W, X and Z are molecules and Y is an atom. C W, Y and Z are molecules and X is an atom. D X, Y and Z are molecules and W is an atom.

1 marks

Answer: B

This question in 0654/11 Oct/Nov 2015

15 Hexane is a covalent compound. Sodium phosphate is an ionic compound. Which row describes the properties of hexane and sodium phosphate? hexane sodium phosphate A high electrical conductivity volatile B insoluble in water non-volatile C non-volatile soluble in water D volatile low electrical conductivity in aqueous solution

1 marks

Answer: B

This question in 0654/13 May/June 2016

14 Which substances exist as covalent molecules? 1 chlorine 2 helium 3 ethanol 4 sodium chloride A 1 and 2 B 1 and 3 C 2 and 4 D 3 and 4

1 marks

Answer: B

This question in 0654/11 Oct/Nov 2016

15 Which row describes the properties of a covalent compound? electrically conductive volatility when molten A high no B high yes C low no D low yes

1 marks

Answer: A

This question in 0654/11 Oct/Nov 2016

16 A model of a molecule is shown. key hydrogen atom boron atom Which row shows the formula of this molecule and describes the type of bonding between the atoms? formula bonding A 2BH3 covalent B 2BH3 ionic C B2H6 covalent D B2H6 ionic

1 marks

Answer: C

This question in 0654/11 Oct/Nov 2016

16 A model of a molecule is shown. key hydrogen atom boron atom Which row shows the formula of this molecule and describes the type of bonding between the atoms? formula bonding A 2BH3 covalent B 2BH3 ionic C B2H6 covalent D B2H6 ionic

1 marks

Answer: C

This question in 0654/12 Oct/Nov 2016

16 A model of a molecule is shown. key hydrogen atom boron atom Which row shows the formula of this molecule and describes the type of bonding between the atoms? formula bonding A 2BH3 covalent B 2BH3 ionic C B2H6 covalent D B2H6 ionic

1 marks

Answer: C

This question in 0654/13 Oct/Nov 2016

15 Which statement about a carbon dioxide molecule is correct? A It is composed of metallic elements, which are covalently bonded. B It is composed of metallic elements, which are ionically bonded. C It is composed of non-metallic elements, which are covalently bonded. D It is composed of non-metallic elements, which are ionically bonded.

1 marks

Answer: C

This question in 0654/12 May/June 2017

14 Which statement describes an oxygen molecule? A It consists of two oxide ions. B It consists of two oxygen atoms. C It consists of two oxygen compounds. D It consists of two oxygen ions.

1 marks

Answer: B

This question in 0654/11 Oct/Nov 2017

17 The electronic structures of carbon and of hydrogen are shown. C H What is the formula of a compound formed between carbon and hydrogen? A CH2 B CH3 C CH4 D C4H

1 marks

Answer: C

This question in 0654/11 Oct/Nov 2017

17 The electronic structures of carbon and of hydrogen are shown. C H What is the formula of a compound formed between carbon and hydrogen? A CH2 B CH3 C CH4 D C4H

1 marks

Answer: C

This question in 0654/12 Oct/Nov 2017

17 The electronic structures of carbon and of hydrogen are shown. C H What is the formula of a compound formed between carbon and hydrogen? A CH2 B CH3 C CH4 D C4H

1 marks

Answer: C

This question in 0654/13 Oct/Nov 2017

14 W, X, Y and Z are diagrams representing atoms and molecules. W X Y Z Which statement is correct? A W and Z are molecules and X and Y are atoms. B W, X and Z are molecules and Y is an atom. C W, Y and Z are molecules and X is an atom. D X, Y and Z are molecules and W is an atom.

1 marks

Answer: B

This question in 0654/11 Oct/Nov 2018

16 Which row describes the properties of a simple covalent compound? conducts electricity conducts electricity boiling point when solid when liquid / °C A no no 60 B no no 2230 C no yes 1400 D yes yes 2850

1 marks

Answer: A

This question in 0654/11 Oct/Nov 2018

14 W, X, Y and Z are diagrams representing atoms and molecules. W X Y Z Which statement is correct? A W and Z are molecules and X and Y are atoms. B W, X and Z are molecules and Y is an atom. C W, Y and Z are molecules and X is an atom. D X, Y and Z are molecules and W is an atom.

1 marks

Answer: B

This question in 0654/12 Oct/Nov 2018

14 W, X, Y and Z are diagrams representing atoms and molecules. W X Y Z Which statement is correct? A W and Z are molecules and X and Y are atoms. B W, X and Z are molecules and Y is an atom. C W, Y and Z are molecules and X is an atom. D X, Y and Z are molecules and W is an atom.

1 marks

Answer: B

This question in 0654/13 Oct/Nov 2018

16 What is the dot-and-cross diagram for a water molecule? A B C D O O O O H H H H H H H H

1 marks

Answer: A

This question in 0654/11 Oct/Nov 2019

16 In which molecule are all the outer electrons of the atoms used in covalent bonds? A CH4 B HCl C H2O D NH3

1 marks

Answer: A

This question in 0654/12 Oct/Nov 2019

16 Which row describes the volatility and electrical conductivity of liquid covalent compounds? electrical volatility conductivity A high high B high low C low high D low low

1 marks

Answer: B

This question in 0654/11 May/June 2020

16 What is a property of a typical covalent compound? A electrical insulator B high melting point C low volatility D soluble in water

1 marks

Answer: A

This question in 0654/12 May/June 2020

16 Which row describes a covalent compound? solubility volatility in water A high low B high high C low low D low high

1 marks

Answer: D

This question in 0654/11 Oct/Nov 2020

16 Which dot-and-cross diagram represents a molecule of ammonia? A B C D H N H H N H H N H H N H H H H H

1 marks

Answer: C

This question in 0654/12 Oct/Nov 2020

16 Which statement about a carbon dioxide molecule is correct? A It is composed of metallic elements, which are covalently bonded. B It is composed of metallic elements, which are ionically bonded. C It is composed of non-metallic elements, which are covalently bonded. D It is composed of non-metallic elements, which are ionically bonded.

1 marks

Answer: C

This question in 0654/11 May/June 2021

16 Which statement about a carbon dioxide molecule is correct? A It is composed of metallic elements, which are covalently bonded. B It is composed of metallic elements, which are ionically bonded. C It is composed of non-metallic elements, which are covalently bonded. D It is composed of non-metallic elements, which are ionically bonded.

1 marks

Answer: C

This question in 0654/12 May/June 2021

16 Which statement about a carbon dioxide molecule is correct? A It is composed of metallic elements, which are covalently bonded. B It is composed of metallic elements, which are ionically bonded. C It is composed of non-metallic elements, which are covalently bonded. D It is composed of non-metallic elements, which are ionically bonded.

1 marks

Answer: C

This question in 0654/13 May/June 2021

16 A model of a molecule is shown. key hydrogen atom boron atom Which row shows the formula of this molecule and describes the type of bonding between the atoms? formula bonding A 2BH3 covalent B 2BH3 ionic C B2H6 covalent D B2H6 ionic

1 marks

Answer: C

This question in 0654/11 Oct/Nov 2021

16 A model of a molecule is shown. key hydrogen atom boron atom Which row shows the formula of this molecule and describes the type of bonding between the atoms? formula bonding A 2BH3 covalent B 2BH3 ionic C B2H6 covalent D B2H6 ionic

1 marks

Answer: C

This question in 0654/12 Oct/Nov 2021

15 Which row describes the properties of a covalent compound? undergoes melting point solubility electrolysis / C in water when molten A 100 insoluble no B 110 soluble yes C 950 insoluble no D 2200 soluble yes

1 marks

Answer: A

This question in 0654/13 Oct/Nov 2021

16 A model of a molecule is shown. key hydrogen atom boron atom Which row shows the formula of this molecule and describes the type of bonding between the atoms? formula bonding A 2BH3 covalent B 2BH3 ionic C B2H6 covalent D B2H6 ionic

1 marks

Answer: C

This question in 0654/13 Oct/Nov 2021

17 The diagram shows the electrolysis of dilute sulfuric acid using inert electrodes. + – dilute sulfuric acid Which row shows the products formed at each electrode and describes the bonding in sulfuric acid? type of anode cathode bonding A oxygen hydrogen ionic B oxygen hydrogen covalent C hydrogen oxygen ionic D hydrogen oxygen covalent

1 marks

Answer: A

This question in 0654/11 May/June 2022

17 The diagram shows the electrolysis of dilute sulfuric acid using inert electrodes. + – dilute sulfuric acid Which row shows the products formed at each electrode and describes the bonding in sulfuric acid? type of anode cathode bonding A oxygen hydrogen ionic B oxygen hydrogen covalent C hydrogen oxygen ionic D hydrogen oxygen covalent

1 marks

Answer: A

This question in 0654/12 May/June 2022

17 The diagram shows the electrolysis of dilute sulfuric acid using inert electrodes. + – dilute sulfuric acid Which row shows the products formed at each electrode and describes the bonding in sulfuric acid? type of anode cathode bonding A oxygen hydrogen ionic B oxygen hydrogen covalent C hydrogen oxygen ionic D hydrogen oxygen covalent

1 marks

Answer: A

This question in 0654/13 May/June 2022

15 The element phosphorus burns in air, as shown. 4P + 5O2 → P4O10 What does the formula P4O10 show? A a mixture of atoms of two elements B a mixture of molecules of two elements C a molecule of a compound D an atom of a compound

1 marks

Answer: C

This question in 0654/11 May/June 2023

16 Which dot-and-cross diagram represents a molecule of ammonia? A B C D H N H H N H H N H H N H H H H H

1 marks

Answer: C

This question in 0654/12 Feb/March 2024

15 Which substances exist as covalent molecules? 1 helium 2 chlorine 3 sodium chloride 4 ethanol A 1 and 2 B 1 and 3 C 2 and 4 D 3 and 4

1 marks

Answer: C

This question in 0654/12 May/June 2024

15 Which substances exist as covalent molecules? 1 helium 2 chlorine 3 sodium chloride 4 ethanol A 1 and 2 B 1 and 3 C 2 and 4 D 3 and 4

1 marks

Answer: C

This question in 0654/13 May/June 2024

16 What is the dot-and-cross diagram for a water molecule? A B C D O O O O H H H H H H H H

1 marks

Answer: A

This question in 0654/11 Oct/Nov 2024

17 Which pair of elements forms a compound that does not conduct electricity when it is molten? A carbon and hydrogen B lithium and bromine C magnesium and chlorine D potassium and iodine

1 marks

Answer: A

This question in 0654/12 Feb/March 2025

18 In which molecule are all the outer-shell electrons of the atoms used to form the covalent bonds? A HCl B H2O C NH3 D CH4

1 marks

Answer: D

This question in 0654/11 May/June 2025

17 Part of the Periodic Table is shown. W X Y Z Which elements form a bond by sharing electrons? A W and X B W and Y C X and Y D Y and Z

1 marks

Answer: C

This question in 0654/11 Oct/Nov 2025

16 Which statement about simple molecules is correct? A They contain both metallic and non-metallic elements. B They have good electrical conductivity. C They contain covalent bonds. D They have high melting points.

1 marks

Answer: C

This question in 0654/12 Oct/Nov 2025

16 Which statement about simple molecules is correct? A They contain both metallic and non-metallic elements. B They have good electrical conductivity. C They contain covalent bonds. D They have high melting points.

1 marks

Answer: C

This question in 0654/13 Oct/Nov 2025