Tuesday, September 9, 2008

Chapter 3: Section 2:

Well today we started off class with the lab and then did the vocab quiz which everyone seemed to do very good on. Everyone did pretty good on the 3.1 quiz too. Oh! We also have some new classmates that just switched into AP Bio! yay Crystal and Adriana!! hehe :)
Anyways these are the notes we took today in class, not that much but its helpful stuff! Especially for the quiz tomorrow...

-Water's solid state is less dense than it's a liquid state, whereas the opposite is true of most other substances. This is because solid water forms a regular crystal lattice structure, in which each water molecule is hydrogen bonded to four other water molecules. the fact that ice is less dense than water enable ice to float on ponds and lakes and ice cubes to float in your glass of soda.

-Water is also an important solvent. (You may recall that the substance that something is dissolved in is the solvent, while the substance being dissolved is the solute. Together they are the solution.) When the solution has water as it's solvent its called an aqueous solution. substances that are water-soluble are hydrophilic substances. they are ionic compounds, polar molecules(sugars), and some proteins. Oils, however, are hydrophobic and non-polar, meaning they do not dissolve in water.

1 comment:

SMABiology said...

Great job. Good to include a picture of the crystal lattice structure so that you can see where the air pockets would go. The air will increase the volume so that the solid form is less dense than the liquid form.