Why do melting points increase across a period?

Related questions

1. Why fluorine is more electronegative than chlorine?
2. What is true electronegativity?
3. Why does electronegativity increase from bottom to top?
4. Why does group 17 have the highest electronegativity?
5. What does a low electronegativity mean?
6. What is Electropositivity and electronegativity?
7. Which is the best definition of electronegativity?
8. Does electronegativity increase from top to bottom?
9. What does it mean to have a higher electronegativity?
10. Why does fluorine have the highest electronegativity?

Tags

1. #melting
2. #number
3. #metallic
4. #metals
5. #aluminium
6. #strength
7. #smaller
8. #because
9. #protons
10. #which
11. #increases
12. #delocalised
13. #boiling
14. #increasing
15. #across
16. #three
17. #atoms
18. #points
19. #magnesium
20. #bonds
21. #contribute
22. #electrons
23. #sodium