GCSE Chem U1 T3 General Revision

Aarav, Poppy, and Anaya are studying the structure of table salt, which is a solid ionic compound. What is the structure of these compounds?

• Giant covalent structure

• Regular arrangement of positive ions in a sea of delocalised electrons

• Ionic lattice consisting of alternate positive and negative ions in a regular arrangement

• Simple molecules with weak forces of attraction between the molecules

Oscar, Evie, and William are discussing the properties of ionic compounds. Which of the following properties can they correctly attribute to ionic compounds?

• Low melting and boiling points

• Does not conduct electricity when solid

• Not soluble in water

• Exist as simple molecules

Sophia, Anaya, and James are studying chemistry and they come across a question. They want to know why the salt they use in their kitchen, which is an ionic compound, has high melting and boiling points?

• Is it because of the weak van der Waal's forces between the salt molecules?

• Is it because of the strong covalent bonds throughout the layers of salt?

• Is it because of the strong ionic bonding in salt that requires substantial energy to break?

• Or is it because of the regular arrangement of positive ions in a sea of delocalised electrons in the salt?

Benjamin, Sophia, and Mia are conducting an experiment in their chemistry class. They noticed that a certain ionic compound does not conduct electricity when it is in a solid state. Why is this the case?

• The ions in the ionic compound are in a fixed lattice and cannot move or carry charge

• The ions in the ionic compound can move and carry charge

• The weak forces of attraction between the molecules of the ionic compound

• The ionic compound has delocalised electrons that are free to move and carry charge

Isla, Aarav, and George are studying for their chemistry exam. They are discussing the way most non-metallic substances exist. Can you help them understand this concept?

• They exist in a giant covalent structure

• They exist in a regular arrangement of positive ions in a sea of delocalised electrons

• They exist in an ionic lattice consisting of alternate positive and negative ions in a regular arrangement

• They exist as simple molecules with weak forces of attraction between the molecules

Eesha, Isabella, and Alexander are working on a science project. They are discussing the strength of covalent bonds. Eesha thinks covalent bonds are strong. Is she correct?

• Yes, they are strong

• No, they are weak

• Depends on the elements involved

• Cannot be determined

Kiara, Emily, and Chloe are studying different materials for their science project. They are particularly interested in the structure of diamond. Can you help them understand what is the structure of diamond?

• Giant covalent structure with each carbon covalently bonded to 4 others in a tetrahedral arrangement

• Giant covalent structure with each carbon covalently bonded to 3 others creating layers

• A single-atom thick layer of graphite with strong covalent bonds between each carbon atom

• Regular arrangement of positive ions in a sea of delocalised electrons

Alexander, Isabella, and Leo are studying different materials for their science project. They are particularly interested in diamonds. Which of the following properties would they associate with a diamond?

• Low melting and boiling points

• Does not conducts electricity

• Extremely soft

• Weak van der Waal's forces of attraction between the layers

Ishaan, Kiara, and Rohan are studying chemistry together. They come across the term 'allotrope' in their textbook. Kiara asks, 'What is an allotrope?'

• A mixture of two or more elements, at least one of which is a metal

• Different forms of the same element in the same physical state

• Attraction between delocalised electrons and the positive ions in a regular lattice

• A single-atom thick layer of graphite with strong covalent bonds between each carbon atom

Max, Thomas, and Alexander are working on a science project about metals and alloys. They are trying to understand why alloys are harder than pure metals. What could be the reason?

• Alloys have low melting and boiling points

• Alloys do not conduct electricity

• Alloys have metallic structures with different sized ions or atoms, which distorts the layers and makes it difficult for them to slide past each other

• Alloys have weak van der Waal's forces of attraction between the molecules