Simple molecules and covalent bonds — Paper 2 · IGCSE Sciences - Co-ordinated (Double) 0654

15 Which covalent molecule contains the most shared pairs of electrons? A CH4 B CO2 C C2H4 D NH3

1 marks

Answer: C

This question in 0654/22 May/June 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 0654/21 Oct/Nov 2018

16 Which dot-and-cross diagram represents the bonding of electrons in a molecule of ethene? A B H H H H C C C C H H H H C D H H H H H C C H H C C H H H H H

1 marks

Answer: A

This question in 0654/21 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 0654/22 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 0654/23 Oct/Nov 2018

16 Which dot-and-cross diagram is not correct? A B C D H H H H H H H H C H C C C C H C C H H H H H H H H

1 marks

Answer: C

This question in 0654/23 Oct/Nov 2018

16 Which dot-and-cross diagram represents the bonding in a molecule of carbon dioxide? A B C D O C O O C O O C O O C O

1 marks

Answer: A

This question in 0654/22 May/June 2020

15 Which dot-and-cross diagram shows the outer shell electrons in a molecule of carbon dioxide? A B C D O C O O C O O C O O C O

1 marks

Answer: A

This question in 0654/23 May/June 2020

15 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 0654/21 Oct/Nov 2020

15 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 0654/22 Oct/Nov 2020

16 Which row explains why the melting points of covalent compounds are lower than those of ionic compounds? covalent compound ionic compound A strong attractive forces strong attraction between molecules between oppositely charged ions B strong attractive forces weak attraction between molecules between oppositely charged ions C weak attractive forces strong attraction between molecules between oppositely charged ions D weak attractive forces weak attraction between molecules between oppositely charged ions

1 marks

Answer: C

This question in 0654/21 May/June 2021

16 Which dot-and-cross diagram represents a molecule of carbon dioxide? A B O C O O C O C D O C O O C O

1 marks

Answer: C

This question in 0654/23 May/June 2021

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 0654/21 May/June 2023

15 Which row identifies the types of elements that form covalent compounds and a physical property 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 0654/22 Feb/March 2024

16 Which dot-and-cross diagram represents the outer-shell electrons in a molecule of methanol? A B H H H C O H H C O H H H C D H H H C O H H C O H H H

1 marks

Answer: A

This question in 0654/21 May/June 2024

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: C

This question in 0654/22 May/June 2024

15 Which row describes the properties of a covalent compound? electrical volatility conductivity when molten A high none B high high C low none D low high

1 marks

Answer: A

This question in 0654/22 May/June 2024

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

1 marks

Answer: A

This question in 0654/21 Oct/Nov 2024

15 Which dot-and-cross diagram shows the outer-shell electrons in a molecule of carbon dioxide? A B C D O C O O C O O C O O C O

1 marks

Answer: A

This question in 0654/21 Oct/Nov 2025

17 Which row shows the dot-and-cross diagrams for nitrogen and ethene? nitrogen ethene H H A N N C C H H H H B N N H C C H H H H H C N N C C H H H H D N N H C C H H H

1 marks

Answer: A

This question in 0654/22 Oct/Nov 2025