9/19/14

This weekend's homework is to complete Assignment 6 based on the reading (the page given in class and 18.1 - which is Chapter 18 Section 1 from Botkin and Keller - your textbook) and your observations/inferences from class. Also, the People's Climate March will be starting from Columbus Circle at 11am on Sunday. If you attend and complete the reflection questions that I post, then I will grant you some extra credit.

Assignment 6 - Investigating the Characteristics of Water

Summarizing

Look over your observations and inferences. On a separate page of looseleaf (that will become your notes about water), write a short summary of what you know/learned about water from your investigations.

Reviewing and Improving Your Understanding

Title the page with your summary, “Why Life on Earth Relies on Water.” You will answer the following questions on this piece of looseleaf.

1. Review and read p. 161 and 162 of Glencoe Biology and the very first section of 18.1 “Water” in Botkin and Keller. Add vocabulary and any information that you deem important to your previous summary.

2. Based on what you now know, why is water a universal component to all life on Earth? Support your answer with vocabulary and observations/inferences.

3. What does the Earth have going for it that allows it to have an abundance of liquid water?

Today's Observations

Procedure	Observations	Inferences
Dissolving We mixed salt and water. We mixed oil and water.	Salt and water mixed well. Oil and water did not mix well. Clumps of oil were visible.	Salt dissolves in water. Oil does not dissolve in water.
Surface tension and cohesion We added drops of water or acetone to surface of a penny and counted how would fit.	Over 30 drops of water fit on a penny. Only about 10 – 20ish drops of acetone fit on the surface of the penny.	Water is cohesive and sticks well to itself (and other surfaces). Acetone is not as cohesive.
Density of solid state. We measured the mass of ice and its volume by displacement.	Approximate density of ice was found to be .5 g/mL, but it is actually 0.9 g/mL.	Ice floats. Ice is less dense than   liquid water. Most substances become more dense as they solidify (b/c their volume decreases).