1. Finding the NaK Demonstrating the properties of the sodium–potassium alloy Education in Chemistry July 2016 rsc.li/EiC416ec

3. K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ positive ions delocalis ed electrons

4. K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ conduct electricity shiny

5. K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ conduct electricity shiny malleable & ductile ductile

6. Li 181  C Na 98  C K 64  C + + + + + + + + + + + + + + + + + +

7. Na + Mg 2+ Al 3+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ conductivity increases … due to extra free electrons? conductivity decreases …but electrons held more weakly?

8. copperzinc + = brass

9. Na sodium K potassium

10. Na sodium K potassium

11. Na 98  C K 64  C

12. Na 98  C K 64  C NaK 80  C ? % K Melting point

13. K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ Na + K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ lattice a regular, repeating arrangement of particles

14. Na + K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ K+K+ weaker attractive forces lower melting point