Metallic Bonding
2 marks · NormalPotassium is a metal.
Draw a labelled diagram to show the arrangement of particles in a metallic lattice of potassium. You may use dots or circles to represent positive ions and crosses or small circles to represent delocalised electrons.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
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Must show: Regular array of positive ions (labelled, e.g. K+), Delocalised electrons shown between ions (labelled or identified)
Also accept: K+ as dots/circles; electrons as crosses/small circles, both clearly separated and labelled
Common mistakes: Missing labels; Ions not in a regular lattice; Confusing electrons with ions
Show mark scheme and worked solution
Marking points
B1 · 1 mark · Regular 2D array of labelled positive ions (e.g., K+).
B2 · 1 mark · Clearly shows and labels delocalised electrons between the ions.
Worked solution
Diagram shows potassium ions (K+) in a lattice, surrounded by a 'sea' of delocalised electrons (e.g., as dots or crosses) with labels.