View source for Melting point and boiling point

The melting point and boiling point are measures of the attractive forces between atoms or molecules. Elements, such as metals, that have strong attractive forces have higher melting points and boiling points than nonmetals, which have very weak forces of attraction. 

==Periodic Trend==

===Halogens===

The physical states of the halogens at room temperature varies from gas to liquid to solid as one moves down the group. As a result, the melting points and boiling points increase as one moves down the group. 

{| width="400" align="center"
! Halogens  	
! Melting Point (K) 
! Boiling Point (K) 
! Physical State at Room Temperature
|-
|align="center"| Fluorine 	
|align="center"| 53 	
|align="center"| 85 	
|align="center"| Gas
|-
|align="center"| Chlorine 	
|align="center"| 173 	
|align="center"| 239 	
|align="center"| Gas
|-
|align="center"| Bromine 	
|align="center"| 266 	
|align="center"| 332 	
|align="center"| Liquid 	 	 	
|-
|align="center"| Iodine	
|align="center"| 387 	
|align="center"| 458 	
|align="center"| Solid  	 	
|}

===Alkali Metals===
The alkali metals show a decrease in melting points and boiling points due to the weaker metallic bonds between atoms as their size increase down the group.

{| width="400" align="center"
! Alkali Metals  	
! Melting Point (K) 
! Boiling Point (K) 
! Physical State at Room Temperature
|-
|align="center"| Lithium 	
|align="center"| 454 	
|align="center"| 1615 	
|align="center"| Solid
|-
|align="center"| Sodium	
|align="center"| 371 	
|align="center"| 1156 	
|align="center"| Solid
|-
|align="center"| Potassium 	
|align="center"| 336 	
|align="center"| 1032 	
|align="center"| Solid 	 	 	
|-
|align="center"| Rubidium	
|align="center"| 312 	
|align="center"| 961 	
|align="center"| Solid  
|-
|align="center"| Cesium	
|align="center"| 301 	
|align="center"| 944 	
|align="center"| Solid  	 	
|}


==Content suitability==
BCIT courses:
<span class="pops">[http://www.bcit.ca/study/outlines/chem0011  CHEM 0011]</span>