Chemistry 0620 · IGCSE
Simple molecules and covalent bonds
100 practice questions on Simple molecules and covalent bonds, with worked solutions and instant marking.
Which type of bond is absent from the structure of ethanol, $\text{CH}_3\text{CH}_2\text{OH}$?
Feb/March 2016
The electronic structures of atoms X and Y are shown. X and Y combine to make a covalent compound. What formula does it have?
Feb/March 2016
Which molecule is made up entirely of single covalent bonds?
Feb/March 2016
The diagrams below show the structures of sodium chloride and nitrogen.
Feb/March 2016
Which row is correct for carbon dioxide as well as methane?
Feb/March 2017
A covalent molecule $M$ has a total of four shared electrons. Identify $M$.
Feb/March 2017
Which row indicates the properties of methane?
Feb/March 2019
Ammonia, $\text{NH}_3$, is a covalent molecule. Which diagram represents the arrangement of outer-shell electrons in an ammonia molecule?
Feb/March 2020
The molecular structure of hydrazine, $\text{N}_2\text{H}_4$, is shown. Which statement about the bonding in hydrazine is incorrect?
Feb/March 2020
In which molecule are all of the outer-shell electrons from each atom involved in forming covalent bonds?
Feb/March 2021
How many electrons take part in the formation of covalent bonds in a molecule of methanol, $\text{CH}_3\text{OH}$?
Feb/March 2021
Magnesium oxide melts at a high temperature. Carbon dioxide melts at a low temperature. Which row shows the attractive forces that are broken when these compounds are melted?
Feb/March 2021
Which molecule contains just two shared pairs of electrons?
Feb/March 2023
Which statement gives a description of methane?
Feb/March 2024
The boiling point of methanal, $\text{CH}_2\text{O}$, is $-19\,^{\circ}\text{C}$. When the temperature is $-20\,^{\circ}\text{C}$, liquid methanal does not conduct electricity. In methanal, each carbon, hydrogen and oxygen atom has a noble gas electronic configuration. This configuration has been obtained by each atom in one of three ways: • gaining electrons • losing electrons • using shared electrons. Which statement explains the bonding between the carbon atom and the oxygen atom in methanal?
Feb/March 2024
In the diagrams below, X and Y represent atoms of different elements. Which diagram correctly shows how the outer-shell electrons are arranged in a methane molecule?
Feb/March 2025
Which covalent compound is shown accurately by the dot-and-cross diagram for the outer-shell electrons?
Feb/March 2025
The table gives the electronic structure of four atoms. W: 2,8,1 X: 2,8,4 Y: 2,8,7 Z: 2,8,8 Which pair of atoms would join together to make a covalent compound?
May/June 2016
The table below gives the electronic structures of four atoms. W: $2,8,1$ X: $2,8,4$ Y: $2,8,7$ Z: $2,8,8$ Which pair of atoms joins together to make a covalent compound?
May/June 2016
The table presents the electronic structures of four atoms. W: $2,8,1$ X: $2,8,4$ Y: $2,8,7$ Z: $2,8,8$ Which two atoms join together to make a covalent compound?
May/June 2016
The table gives the electronic structures of four atoms: W ($2,8,1$), X ($2,8,4$), Y ($2,8,7$), Z ($2,8,8$). Which two atoms join together to make a covalent compound?
May/June 2016
The table gives the electronic structures of four atoms. W: $2,8,1$ X: $2,8,4$ Y: $2,8,7$ Z: $2,8,8$ Which pair of atoms joins together to make a covalent compound?
May/June 2016
Which statement describes the attractive forces acting between molecules (intermolecular forces)?
May/June 2016
The table gives the electronic structure of four atoms. Which two atoms join together to make a covalent compound?
May/June 2016
Which molecule has precisely two single covalent bonds?
May/June 2017
Which arrangement of outer-shell electrons in a covalent compound is correct?
May/June 2017
Compound X has a melting point of $71^\circ\text{C}$ and a boiling point of $375^\circ\text{C}$. Which of the following statements about X is correct?
May/June 2017
Which of the following statements about an ammonia molecule, $\text{NH}_3$, is correct?
May/June 2017
Water is a compound with simple covalent bonding.
May/June 2017
Covalent molecule Q has six electrons shared in total. What is Q?
May/June 2018
The four organic compounds below are given: ethane, ethanoic acid, ethanol and ethene. Which bond is found in each of the four compounds?
May/June 2018
The bonding pattern between elements X and Y in compound $\text{XY}_2$ is illustrated. $\text{Y} = = \text{X} = = \text{Y}$ Which row gives the bond type in $\text{XY}_2$ and the kind of element X?
May/June 2018
Which substances are structured in a similar way?
May/June 2018
The nine gases listed are: ammonia carbon monoxide chlorine ethane ethene helium hydrogen neon oxygen
May/June 2018
Seven gases are listed below. ammonia ethene helium hydrogen hydrogen chloride methane nitrogen
May/June 2018
Which row gives the description of how single covalent bonds form in methane?
May/June 2019
Which row explains how single covalent bonds form in methane?
May/June 2019
Which row shows how single covalent bonds are formed in methane?
May/June 2019
Which row shows how single covalent bonds are formed in methane?
May/June 2019
Which row gives the description of how single covalent bonds form in methane?
May/June 2019
Which row explains the formation of single covalent bonds in methane?
May/June 2019
The diagrams display part of the structures of five substances, A, B, C, D and E.
May/June 2019
This question concerns phosphorus and phosphorus compounds.
May/June 2019
A covalent molecule Q has just six shared electrons. What is Q?
May/June 2021
Which substance is a diatomic covalent molecule that occurs in pure dry air?
May/June 2021
Covalent molecule Q has only six shared electrons. What is the identity of Q?
May/June 2021
A covalent molecule Q has only six shared electrons. Identify Q.
May/June 2021
Element R produces a covalent compound $R_2Si$ with silicon. Which row identifies R?
May/June 2021
Covalent molecule Q has only six shared electrons. What molecule is Q?
May/June 2021
Molecule Q is covalent and has only six electrons shared between atoms. Identify Q.
May/June 2021
A covalent molecule Q has only six electrons that are shared. What is Q?
May/June 2021
Which dot-and-cross diagram shows how the outer-shell electrons are arranged in a hydrogen chloride molecule?
May/June 2022
Which molecule has more than one pair of electrons that are shared?
May/June 2022
Which diagram shows the arrangement of outer-shell electrons in a nitrogen molecule?
May/June 2022
Which dot-and-cross diagram represents how the outer-shell electrons are arranged in a hydrogen chloride molecule?
May/June 2022
This question concerns sulfur compounds.
May/June 2022
Fluorine together with chlorine belongs to the halogen group.
May/June 2022
This question concerns nitrogen and compounds containing nitrogen.
May/June 2022
Which row explains the formation of single covalent bonds in methane?
May/June 2023
Ammonia, $\text{NH}_3$, forms a covalent molecule. Which diagram illustrates the outer-shell electron arrangement in a molecule of ammonia?
May/June 2023
In which molecule are all outer-shell electrons used for covalent bonding?
May/June 2023
Which statement explains the way the C-H bonds in methane gas in the atmosphere help to cause global warming?
May/June 2023
Which row shows how single covalent bonds are formed in methane?
May/June 2023
Ammonia, $\text{NH}_3$, is a covalent molecule. Which diagram illustrates the arrangement of outer-shell electrons in an ammonia molecule?
May/June 2023
In which molecule do all the outer-shell electrons take part in covalent bonding?
May/June 2023
This item concerns non-metals and compounds made from non-metals.
May/June 2023
This question concerns non-metals.
May/June 2023
A covalent molecule, M, has four shared pairs of electrons. What is the identity of M?
May/June 2024
Which of the following statements about bonding is correct?
May/June 2024
A compound, $\text{CH}_3\text{Cl}$, is given with three statements. Which of the statements are correct?
May/June 2024
In one molecule of nitrogen and in one molecule of ethene, how many electrons are shared?
May/June 2024
Which diagram illustrates how the outer shell electrons are arranged in a water molecule?
May/June 2024
Which molecule has a double covalent bond connecting two atoms of the same element?
May/June 2024
Fig. 1.1 presents the structures of seven substances, A, B, C, D, E, F and G.
May/June 2024
Which substances have one or more pairs of electrons shared between atoms?
May/June 2025
The diagrams illustrate the structures of four molecules. Which statement about these molecules is correct?
May/June 2025
In the molecules $\text{CH}_4$, $\text{HCl}$ and $\text{H}_2\text{O}$, which atoms make use of all the electrons in their outer shells for bonding?
May/June 2025
Which dot-and-cross diagram shows the electronic arrangement of the outer-shell electrons in ammonia, $\text{NH}_3$?
May/June 2025
Which dot-and-cross diagram shows the arrangement of outer-shell electrons in a molecule of nitrogen?
May/June 2025
This question concerns ionic and covalent compounds.
May/June 2025
This question focuses on ionic compounds and simple molecular compounds.
May/June 2025
This question concerns covalent compounds.
May/June 2025
Which row gives the description of how single covalent bonds are formed in methane?
Oct/Nov 2016
The structure of ethanoic acid is shown. Which diagram represents the arrangement of outer shell electrons in an ethanoic acid molecule?
Oct/Nov 2016
Benzene is a liquid whose molecular formula is $\text{C}_6\text{H}_6$. Ethene is a gas whose molecular formula is $\text{C}_2\text{H}_4$. Which statement is right?
Oct/Nov 2016
The structure of methanal is shown. Which diagram illustrates the arrangement of outer-shell electrons in a methanal molecule?
Oct/Nov 2016
Ethanol is a liquid at room temperature and has a boiling point of $78^\circ\text{C}$. Sodium chloride is a solid at room temperature. Which statement about the bonding in ethanol and sodium chloride is not correct?
Oct/Nov 2016
The molecules $\text{N}_2$, $\text{C}_2\text{H}_4$, $\text{CO}_2$ and $\text{CH}_3\text{OH}$ each contain covalent bonds. These bonds are made up of pairs of electrons that are shared. Which row shows the total number of shared electron pairs in the molecules illustrated?
Oct/Nov 2016
Which row states the type of bonding found in substances 1 and 2?
Oct/Nov 2017
Which dot-and-cross diagram represents the outer-shell electron arrangement in a nitrogen molecule?
Oct/Nov 2017
Which dot-and-cross diagram illustrates the arrangement of outer-shell electrons in a carbon dioxide molecule?
Oct/Nov 2017
Which dot-and-cross diagram illustrates the outer-shell electron arrangement in a molecule of carbon dioxide?
Oct/Nov 2017
The diagram presents the structures of five substances, A, B, C, D and E. A: a ring made up only of sulfur atoms linked by single covalent bonds. B: a molecule in which sulfur is bonded to two hydrogen atoms. C: a structure with two carbon atoms joined together, hydrogen atoms attached, and a sulfur atom bonded to hydrogen. D: a molecule showing sulfur double-bonded to two oxygen atoms. E: a molecule in which two sulfur atoms are bonded together, with each sulfur also bonded to a chlorine atom. Use only the structures shown in the diagram to answer the questions below. Each structure may be chosen once, more than once or not at all.
Oct/Nov 2017
Which pair of compounds are molecules that both have a double bond?
Oct/Nov 2018
Strontium nitrate is an ionic compound. Cyclohexane is a covalent compound. Which row gives a property of each compound?
Oct/Nov 2018
Which two compounds are molecules that each contain a double bond?
Oct/Nov 2018
Which two compounds are molecules that each have a double bond?
Oct/Nov 2018
How many electrons take part in the covalent bonds in one molecule of methanol, $\text{CH}_3\text{OH}$?
Oct/Nov 2018
Which covalent molecule has two atoms joined together by exactly four shared electrons?
Oct/Nov 2018
The formula for ammonia is $\text{NH}_3$. Which statement is correct about one molecule of ammonia?
Oct/Nov 2018