Saturday, November 27, 2010
Cohesion- The intermolecular force that holds together molecules in a solid ot liquid.
Surface tension- surface tension is a force present within the surface layer of a liquid that causes the layer to behave as an elastic sheet.
We had to write our hypothesis and the observations we saw when we were doing this lab. We also had partners, my partner was Alfie. What we did in the lab was have to put different types of liquid on a coin and record the number of drops that fell on the coin. The second part was using wax paper, and we put different types of liquid on it, and used a toothpick to spread the water around the wax paper, by doing that we see which ones have a higher surface tension and which one shave a lower surface tension.
My hypothesis was that by changing the type of liquid, you change the surface tension, my hypothesis was correct. Some observation I made were that more drops of plane water could fit on the coin rather than putting the coin in soap, taking out, and then putting water on it. When there was just water, the bubble of water on the coin popped, and with the soap the water drops just glided right off the coin and onto the paper towel. When me and Alfie were doing wax paper, the regular water had the most surface tension because we could move it around the most, what would happen was it would hold a certain amount, and then it would drop all the water and start collecting water again, and then it would repeat, that is cohesion. The second liquid with the second highest surface tension was the ''unknown liquid.'' Then it was the green soap that had the least surface tension.
Tuesday, November 23, 2010
http://www.youtube.com/watch?v=jRfEGvp6wDU&feature=player_embedded (cool video about it)
http://www.dogonews.com/2010/10/9/will-drilling-into-a-volcano-save-naples (article link)
Sunday, November 21, 2010
Tuesday, November 16, 2010
Monday, November 15, 2010
The ingredients are (stirred) in. If left alone, they will settle out. The heavier ingredient will settle to the bottom. Filtration can separate the two ingredients. An example would be dirt mixed with water.
The size of the solute is smaller than in a suspension, but greater than in a solution (see below). The solute breaks down but remains as a clump of molecules and is smaller than the eye can see. Colloids are a bit unusual in that the solute is equally dispersed in the solvent as in a solution, but the solute does not completely break down. In many cases this is because something coats the bits of solute and prevents them from completely dissolving in the solvent. An example would be mayonnaise, jello or oobleck
''The solute and solvent are dissolved and cannot be separated unless one of the ingredients changes state of matter. ie. distilation, (evaporating) or crystallation. An example would be salt and water.''
salty water (dissolved)
sugar water (dissolved)
brewed tea or coffee
brass (a buttery yellow alloy of zinc and copper http://www.wisegeek.com/what-is-brass.htm)
- Beach sand
- basically anything that has multiple parts
This is a video to show you what corn starch can do.
When i made oobleck what happened was when i held it in my hands and was doing something to it it stayed and the second I relaxed it became a complete liquid and flew down. Also when i pounded it, it w2as a solid and when i dipped my hand in it, it was a liquid.When we did this is class me and my partner put to much water in the corn starch. The corn starch made it softer and more liquid like than all the other ones. Then we took some water out and it became harder. In the end we were pretty successful. Now it is drying and becoming corn starch again!
Sunday, November 7, 2010
Wednesday, November 3, 2010
Tuesday, November 2, 2010
State of Matter
An indefinite volume
Has a definite mass
An indefinite shape
It expands real large
Oxygen, Helium, and carbon dioxide
A definite volume
Has a definite mass
An indefinite shape
Coke, water, Fanta
Has a definite volume
has a definite mass
Has a definite shape
Almost no compressibility
Expands real low
Wood, brick, glass, and rubber