Why is it that we tend to look at period 3 elements when studying trends in

[Tea/Coffee]

melting points, solubility, etc? I am doing a Alevel chemistry course and it seems that when studying trends such as melting points and solubility, or trends of oxides etc. We generally look at the period 3 and beyond not perioid 2, why?

 

[ArturoGonzales]

Convenience.

Period 3 offers the greatest variability and most consistency with most trends. Period 2 kind of has a steep drop off.

Those beyond period 3 often deal with transition metals, in which there are always many exceptions/oddly behaving elements.

Refer to image:
http://periodictable.com/Properties/A/BoilingPoint.st.log.gif