GCSE CHEMISTRY INTRODUCTION EXAM REVISION QUESTIONS
WITH VERIFIED SOLUTIONS LATEST 2025 UPDATE.
What is covalent bonding? - ANSWER- when atoms of non-metallic elements join together by
sharing electrons
What do covalent bonds form? - ANSWER- molecules
What does the number of covalent bonds depend on? - ANSWER- the number of electrons it
need to achieve a stable electronic structure
How are atoms in a metal arranged? - ANSWER- - closely packed together and arranged in
regular layers
- the electrons in the highest energy level are delocalised
- the strong electrostatic forces between these electrons and the positively charged metal ions hold
the metal together
What is electrostatic? - ANSWER- It is generated by differences in electrical charge or can
refer to energy at rest.
What are the properties of giant ionic structures? - ANSWER- - many strong electrostatic forces
hold the ions together
- high melting points
- high boiling points
- cannot coduct electricity in solid as the ions can only vibrate around fixed positions
- conductors of electricity when molten/dissolved in water as ions are free to move in solution
,What are the properties of simple molecules? - ANSWER- - strong covalent bonds
- low melting point
- low boiling point
- don't conduct electricity as molecules have no overall charge, so cannot carry electrical charge
Why do simple molecules have low melting and boiling points? - ANSWER- because the
intermolecular forces between the molecules are weak
- these forces are overcome when a molecular substance melts or boils
- this means that substances made of small molecules have low melting and boiling points
What are the properties of giant covalent structures? - ANSWER- - every atom in the structure
is joined to several other atoms by strong covalent bonds
- very high melting points
What are examples of giant covalent structures? - ANSWER- - diamond
- graphite
What is a compound? - ANSWER- when two or more elements react together
What is an atoms? - ANSWER- the smallest part of an element that can still be recognised as
that element
What is a molecule? - ANSWER- when atoms join together by chemical bonds
What is an ion? - ANSWER- a charged particle produced by the loss or gain of electrons
, How do the atoms of elements gain stable electronic structures? - ANSWER- joining together
by sharing electrons, or by transferring electrons
What atoms have stable electronic structures? - ANSWER- atoms of the noble gases
What is ionic bonding? - ANSWER- - when metallic elements react with non-metallic elements
they produce ionic compounds
- metal atoms lose electrons to become positively charged ions
- non-metal atoms gain electrons to become negatively charged ions
- the oppositely charged particles attract each other in the ionic compound
What do the ions in ionic bonding form? - ANSWER- giant structures of lattices
What is a lattice? - ANSWER- regular grid-like arrangement of atoms in a material
What do we use to represent atoms and ions involved in forming ionic bonds? - ANSWER- -
dot and cross diagrams
- in these diagrams we only show the electrons in the outermost shell of each atom or ion
Why are ionic compounds neutral? - ANSWER- because the charges on the ions in ionic
compounds cancel out eachother
How can we work out the formula of an ionic compound? - ANSWER- by balancing the
charges
WITH VERIFIED SOLUTIONS LATEST 2025 UPDATE.
What is covalent bonding? - ANSWER- when atoms of non-metallic elements join together by
sharing electrons
What do covalent bonds form? - ANSWER- molecules
What does the number of covalent bonds depend on? - ANSWER- the number of electrons it
need to achieve a stable electronic structure
How are atoms in a metal arranged? - ANSWER- - closely packed together and arranged in
regular layers
- the electrons in the highest energy level are delocalised
- the strong electrostatic forces between these electrons and the positively charged metal ions hold
the metal together
What is electrostatic? - ANSWER- It is generated by differences in electrical charge or can
refer to energy at rest.
What are the properties of giant ionic structures? - ANSWER- - many strong electrostatic forces
hold the ions together
- high melting points
- high boiling points
- cannot coduct electricity in solid as the ions can only vibrate around fixed positions
- conductors of electricity when molten/dissolved in water as ions are free to move in solution
,What are the properties of simple molecules? - ANSWER- - strong covalent bonds
- low melting point
- low boiling point
- don't conduct electricity as molecules have no overall charge, so cannot carry electrical charge
Why do simple molecules have low melting and boiling points? - ANSWER- because the
intermolecular forces between the molecules are weak
- these forces are overcome when a molecular substance melts or boils
- this means that substances made of small molecules have low melting and boiling points
What are the properties of giant covalent structures? - ANSWER- - every atom in the structure
is joined to several other atoms by strong covalent bonds
- very high melting points
What are examples of giant covalent structures? - ANSWER- - diamond
- graphite
What is a compound? - ANSWER- when two or more elements react together
What is an atoms? - ANSWER- the smallest part of an element that can still be recognised as
that element
What is a molecule? - ANSWER- when atoms join together by chemical bonds
What is an ion? - ANSWER- a charged particle produced by the loss or gain of electrons
, How do the atoms of elements gain stable electronic structures? - ANSWER- joining together
by sharing electrons, or by transferring electrons
What atoms have stable electronic structures? - ANSWER- atoms of the noble gases
What is ionic bonding? - ANSWER- - when metallic elements react with non-metallic elements
they produce ionic compounds
- metal atoms lose electrons to become positively charged ions
- non-metal atoms gain electrons to become negatively charged ions
- the oppositely charged particles attract each other in the ionic compound
What do the ions in ionic bonding form? - ANSWER- giant structures of lattices
What is a lattice? - ANSWER- regular grid-like arrangement of atoms in a material
What do we use to represent atoms and ions involved in forming ionic bonds? - ANSWER- -
dot and cross diagrams
- in these diagrams we only show the electrons in the outermost shell of each atom or ion
Why are ionic compounds neutral? - ANSWER- because the charges on the ions in ionic
compounds cancel out eachother
How can we work out the formula of an ionic compound? - ANSWER- by balancing the
charges
