Work through the list without notes. If you cannot do a statement, follow its link, then come back. Guide = study guide; Practice = practice questions.
Understanding
- I can describe metallic bonding as the attraction between positive ion cores and a sea of delocalized valence electrons. (Guide: “A different kind of solid”; Practice Q1)
- I can explain why a metal is neutral overall even though its cores are positive. (Guide: “Drawing the electron-sea model”)
- I can explain the difference between an interstitial alloy and a substitutional alloy, with steel and brass as examples. (Guide: “Alloys”; Figure 2)
- I can explain why an alloy is a mixture and not a compound. (Guide: FAQ; Revision notes)
Skills
- I can draw a particulate model of a metal with equal cores in a regular array, the correct core charge and the correct number of delocalized electrons. (Guide: Figure 1; Practice Q6)
- I can draw particulate models of a substitutional alloy and an interstitial alloy that show where the added atoms sit. (Guide: Figure 2)
- I can classify an alloy as interstitial or substitutional from atomic radii, using percent difference. (Guide: Worked example 1; Practice Q2, Q7)
- I can convert between an alloy’s mass percent and its atom ratio, and use the result in a model. (Guide: Worked examples 2 and 3; Practice Q4, Q5, Q7)
Reasoning
- I can explain why metals conduct electricity and why alloys still conduct. (Practice Q6)
- I can explain why metals are malleable while ionic solids are brittle. (Practice Q3)
- I can explain why interstitial atoms make an alloy harder and less malleable or ductile. (Guide: “How alloying changes properties”; Practice Q6)
- I can evaluate a claim about where added atoms sit in an alloy. (Practice Q7)
All ticked? Move on to Topic 2.5, Lewis Diagrams, or return to the course roadmap.