Monday, March 22, 2010

Apologia Physical Science, Module 4, The Wonder of Water

Interactive Study Links
• Making flashcards at Quizlet.com is a great way to study!  Create an account to be able save your flashcard sets to practice every day.  You can make cards for whatever you need to study in the chapter, not just vocabulary.  Here are some examples, but be careful if you use these; some have had errors.  You will learn a lot more if you make your flashcards yourself.
Hydrogen Bonds Animation - short fun animation

Other Study Links
How to read a meniscus - why it can be difficult to get an accurate measurement
Penny/Paperclip Lab - love the fill-in sheet at the end
Hydrogen Bonding and the boiling point of water, and how water (H2O) behaves differently than other H2__ substances (H2S, H2Se, and H2Te -- and these are mentioned in the texbook).
Snow Globe Lab - really cool, and if you don't want to actually make snow globes, you can simply let the class experiment and see which solvents dissolve which solutes, and to learn about the polar and non-polar properties.
Surface Tension, Cohesion, Adhesion - great information, and love the examples section.
• Module 4 Practice Page - created by Debbie
►See most of these and more at Debbie's Educator's Resources.  (Thanks, Debbie!)

Also thanks to Debbie for her hard work in locating about half of these videos and posting them on her class website.  So glad I found her last year!  =D






(1) p. 81-84, The Composition of Water











(2) p. 85, Chemical Formulas

Chemical symbols:
     hydrogen: H     oxygen: O     carbon: C     sodium: Na     chloride: Cl

Chemical Formulas:
     water: H2O     carbon dioxide: CO2     table salt (sodium cloride): NaCl









(3) p. 86-89, Water's Polarity

Sharing electrons is what causes atoms to "stick" together to become molecules.

Sharing Electrons



Because water molecules are polar, see this image to understand how water molecules in a stream of water will "flip" so that their positive ends are attracted toward the negative charges on a balloon that has been rubbed in your hair, causing the stream of water to bend.  (image source)










(4) p. 90-93, Water as a Solvent

Atoms generally have the same number of protons (positive) and electrons (negative), and therefore have no net electrical charge.  (Is neither more positive or more negative)
Atoms cannot gain or lose protons, but they can gain or lose electrons.
If an atom gains/loses electrons, it has an imbalance of charges and is now an ion.

Sodium ions have lost an electron, and are positive.
Chloride ions have gained an electron and are negative.
Sodium Chloride (table salt - NaCl) is an ionic molecule.

In a saltwater solution, water is the solvent, and salt is the solute.
Since water is polar, it is able to dissolve salt.  Polar solvents can dissolve either polar or ionic solutes.
Nonpolar solutes can only be dissolved by nonpolar solvents.












(5) p. 93b-97, Hydrogen Bonding in Water

Chemical bonding links atoms together to form molecules.
Hydrogen bonding links molecules together.
Chemical bonds are stronger than hydrogen bonds.  You can boil water to break the hydrogen bonds, unlinking the molecules, but the chemical bond still holds the molecules together - a water vapor, or gas, of microscopic water molecules.

Water cannot hydrogen bond when it is in a solid state - ice!
That is why water is expanded when frozen and why it floats -- its molecules are further apart than when a liquid, so ice is less dense than water.

• Hydrogen Bonds Animation - short fun animation
• Hydrogen bond image

Properties of Water



More about hydrogen bonding.





Water Molecules - part 1 is a great video animation that shows that water molecules are polar, and will hydrogen bond.  Hydrogen bonding is what enables water to stay in a liquid form at room temperature (instead of a gas like other H2__ substances).



Water Molecules - part 2 shows the state of water molecules in liquid form, as a solid, and as a gas.









(6) p. 97b-99a, Water's Cohesion

Surface tension is caused by cohesion.



It would be cool to drink that glob of water, haha!
(And how different can two people's hair be??? Love hers... but his...?  He needs gravity, lol.) =D




cohesion - how water sticks to itself
adhesion - how water sticks to other things

Mercury has very little adhesive properties, but strong cohesion.








(7) p. 99b-100, Hard Water and Soft Water






From Wikipedia:
"In chemistry, a solution is a homogeneous mixture composed of only one phase. In such a mixture, a solute is a substance dissolved in another substance, known as a solvent. The solvent does the dissolving. The solution more or less takes on the characteristics of the solvent including its phase, and the solvent is commonly the major fraction of the mixture. The concentration of a solute in a solution is a measure of how much of that solute is dissolved in the solvent."
Read full article.  Really good!


Monday, March 15, 2010

Apologia Science, Module 3, The Atmosphere

Interactive Study Links:
• Making flashcards at Quizlet.com is a great way to study!  Create an account to be able save your flashcard sets to practice every day.  You can make cards for whatever you need to study in the chapter, not just vocabulary.  Here are some examples but be careful if you use these; some have had errors.  You will learn a lot more if you make your flashcards yourself.

Other Study Links:
Air Experiments at Science Matters.  Looks like most all these can be done with items around the house.  We are doing several from this website!
Top Ten Air Pressure Experiments at The Homeschool Mom
Egg/Balloon in a Bottle (Also see this Steve Spangler video illustration)
Layers of the Atmosphere - VERY good, concise explanation!  With links to visuals.
See these and more at Debbie's Educator's Resources.  (Thanks, Debbie!)



at·mos·phere  at'-mə-sfir n.
1. The gaseous mass or envelope surrounding a celestial body, especially the one surrounding the earth, and retained by the celestial body's gravitational field.
2. The air or climate in a specific place.
  • lithosphere - land
  • atmosphere - air
  • hydrosphere - water
  • biosphere - life

The ozone layer is in the stratosphere.
Most weather occurs in the troposphere.








(1) p. 57-61, Atmospheric Pressure



Sinking air gives us high pressure  and clears out the skies.
Low pressure allows the clouds to build up and you'll likely have weather.
►76 cm or 760 mm = 29.92 inches, which equals 1 atm.



What happens if there is NO Air Pressure!  Very fun video!








(2) p. 61b-62, The Layers of the Earth's Atmosphere

The atmosphere is made up of 2 main layers, which are further divided into more layers.
I.  Homosphere
     A.  Troposphere (0-11km)
          1. We live here.
          2. 78% nitrogen, 21% oxygen, 1% other gases
          3. Most weather occurs here.
     B.  Stratosphere (11-50km)
          1.  Jet stream
          2.  Ozone layer
     C.  Mesosphere (50-80km)
          1.  Meteor showers
II.  Heterosphere
     A.  Thermosphere
     B.  Exosphere

►Learn more about each layer here.        


To help you remember the difference between homosphere (even though as one goes higher, and the molecules are fewer, the percentage of gases is the same all the way up) and heterosphere (the mixtures are different at different levels)








(3) p. 63-66, The Homosphere

The layers of the Homosphere:
     Troposphere, Stratosphere, Mesosphere




►Another atmosphere video, this one showing scenes from when Joe Kittenger sky-jumped from over 19 miles from an air balloon!  That is way up in the stratosphere!



►It is very important to remember that the concentration of gases in the homosphere -- throughout the troposphere, the stratosphere, and the mesosphere -- changes at the same rate, the higher you go.
--A steady change like this is called a gradient.  
So the concentration gradient decreases with increasing altitude.
It is still 78% nitrogen, 21% oxygen, and 1% other, but it isn't as concentrated.  There are fewer and fewer molecules the higher you go.
Air pressure does the same -- decreases with increasing altitude.  You don't usually notice this unless you travel up or down a mountain or fly in a plane.  Then your ears might pop!




The temperature in the troposphere also decreases with increasing altitude, but in the stratosphere, this switches!  Then in the mesosphere, it switches back!
So the temperature gradient does not stay the same all the way up through the homosphere.







(4) p. 67-70a, What is Temperature?












(5) 70-71, The Temperature Gradient in the Homosphere

We learned that the concentration of gases that we breathe (nitrogen 78%, oxygen 21%, other 1%) changes at a steady rate from ground level all the way up through the three layers of the homosphere.  This steady rate is called a gradient.  More specifically, this is a concentration (of gases) gradient.
It is still 78% nitrogen, 21% oxygen, and 1% other, but it isn't as concentrated.  There are fewer and fewer molecules the higher you go.
It stays this way until it reaches the heterosphere, where there begins to be different kinds of gases at different levels.

The temperature changes in the homosphere also, and is called a temperature gradient.

The difference is that the temperature gradient (rate of change), changes with each layer.  Yes, a rate of change changes!
Through the lowest level of the homosphere (the troposphere), the temperature decreases as the altitude increases, just like the concentration gradient, and the pressure gradient.
But when you get to the stratosphere, the temperature gradient switches!  As the altitude increases in the stratosphere, the temperature increases.
When you get to the mesosphere, it switches back, once again decreasing as the altitude increases.

Why does this happen?
The ozone layer is in the stratosphere, and it absorbs the ultraviolet rays of the sun, and the energy of those rays.  So temperatures increase in this layer.



The temperature gradient within the troposphere gets colder the higher you go.








(6) p. 71-75a, The "Hole" in the Ozone Layer

I could find no videos for this section, so here are a few facts.

First, it isn't really a hole.  It is a thinning.
It is directly over Antarctica.
It occurs from August to sometime in November every year, caused by a weather phenomenon called the Polar Vortex.
After this period of time, the "hole" returns to normal thickness for the rest of the year.
Chlorofluorocarbons (CFCs) are completely non-toxic.
The ozone "hole" was discovered in 1956 before CFCs were being widely used.







(7) p. 75-76, The Heterosphere


Mysteries of the Sun: Ionosphere, Thermosphere, and Mesosphere from Science@NASA on Vimeo.



Monday, March 8, 2010

Apologia Physical Science, Module 2, Air

Interactive Study Links:
• Making flashcards at Quizlet.com is a great way to study!  Create an account to be able save your flashcard sets to practice every day.  You can make cards for whatever you need to study in the chapter, not just vocabulary.  Here are some examples, but be careful if you use these; some have had errors.  You will learn a lot more if you make your flashcards yourself.

Other Study Links:
Keeping Dry - short experiment that shows air does take up space
Look at one Part per Million - simple illustration that shows just how much one part per million really is!  (Scroll to page 6)
See these and more at Debbie's Educator's Resources.  (Thanks, Debbie!)


(1) p. 28-29, The Air and Humidity





Relative Humidity Demo
Parents/educators, this would be a great one to do in class!  =)








(2) p. 30-33, The Composition of Air

Concentration of oxygen = combustion!  (Experiment "Oxygen and Fire")
Video of engineers at Purdue University in 1995 lighting a grill with liquid oxygen.
Do not try this at home!








(3) p. 33-38a, Carbon Dioxide in the Air

The Greenhouse Effect is a good thing.






























The Greenhouse Effect
The "atmosphere" mentioned in the video is the ozone layer that is in the stratosphere (one of the layers in our atmosphere).





(4a) Global Warming, p. 38-43

In the following video:
--"My whole career, he's been going around saying, 'The climate changes all the time; get used to it.' " (at 2:25)
--"Cause and effect...  Temperatures go up, then CO2 concentrations go up; CO2 does not drive temperature."  (at 5:50)
--"We know now for certain that the temperature changes before the CO2..."  (at 5:30)
--"When I started out in 1970's, global cooling was the consensus."  (at 1:20)












In your textbook, we see that:
1% of one million is 10,000 parts of that million.
1% of 1,000,000 = 10,000 ppm.

Joe Bastardi (buh-STAR-dee) tells that carbon dioxide increases 1.5 ppm a year.
And that humans contribute 3% of that.  So human contribution is 1 part out of 20 million.  Per year!


Is Joe Bastardi correct?  Is 3% of 1.5 ppm equal to 1 part of 20 million???

1.5/1,000,000 = 30/20,000,000
And 3% of 30 = 0.9.  So rounding it up, it is indeed 1 part out of 20 million.

Getting back to the one million, 1.5 ppm is the same as $1.50 out of $1,000,000.
What is 3% of 1.5?
     0.03 x 1.5 = .045
So comparing the human contribution of carbon dioxide of the air to money, that is 4½ cents out of $1 million dollars.



►If 10,000 pmm is only 1% of a million, are you curious as to what percentage of a million is 1 ppm?
Use the formula:  ___ is what percentage of ____.
Fill in with the correct numbers.
      1 ppm  is what percentage of  1,000,000.
Put in an = sign for the word "is" and the "x" sign for the word "of."
     1 ppm = ___% x 1,000,000.
Divide both sides by 1,000,000.
     1 ppm = .0004%
That's four ten-thousandths of a percent!



►Review the Factor/Label method below.  Apply this method to learn how to figure percentages of ppm.
I had some students tell me, "But we didn't learn that one...." (on the videos, or in class, etc.) when doing the conversion problems I had sent home with them in Module 1.
Being able to apply something to another similar problem shows you learned it.  ;)

(4b) Review of the Factor/Label method, p. 42-43












(5) Ozone, p. 43-45

Ozone is the earth's natural sunscreen.  It screens ultraviolet radiations, or UV rays.


Link








(6) Air Pollution, p. 45-51

This section talks about different kinds of air pollution and what has been done about them, and whether or not it is beneficial to spend huge amounts of money trying to get rid of other lesser pollutants.

In your textbook, many different kinds of oxides mentioned.
Wikipedia says, "An oxide is a chemical compound containing an oxygen atom and other elements.  Most of the earth's crust consists of oxides.  Oxides result when elements are oxidized by air (when oxygen in the air reacts with the element.)"
A list of well-known oxides.

Mentioned in your book are:
sulfur oxides (of which there is a sulfur dioxide and a sulfur trioxide), carbon monoxide, carbon dioxide, and nitrogen oxides.  You've probably heard of other 'oxides' such as hydrogen peroxide.
(Notice the above prefixes mon-, di-, tri-.)


How a Catalytic Converter converts gases




Cost/Benefit Analysis, or CBA.




Monday, March 1, 2010

Apologia Physical Science, Module 1, The Basics

What we did 2010, 2012-13

Interactive Study Links
• Making flashcards at Quizlet.com is a great way to study!  Create an account to be able save your flashcard sets to practice every day.  You can make cards for whatever you need to study in the chapter, not just vocabulary.  Here are some examples, but be careful if you use these; some have had errors.  You will learn a lot more if you make your flashcards yourself.

Other Study Links
Unit Multipliers at Donna Young
Practice Conversions
• Convert a holiday recipe
See these and more at Debbie's Educator's Resources.  (Thanks, Debbie!)



(1) p. 1-6, Atoms and Molecules

Molecules in Solids and Liquids  (for younger kids, but still works!)
(Same as "Eureka!" Episodes 1617 combined.) 





Molecules are made of two or more atoms.

Eureka! Episode 22 - Atoms





Basically atoms and elements are the same thing. 
An atom is just the smallest amount of an element.
Read this ice cream analogy.




Eureka! Episode 23 - Electrons



Making Molecules with Atoms



►The Periodic Table of Elements with the names of the elements.
Some of the names of elements are copper, iron, and aluminum, carbon, oxygen, and helium, or potassium, calcium, and zinc.


Do you have any gold jewelry?  How can you know if it is pure gold or not?


Atoms and Molecules
Elements (atoms or molecules) and Compounds (a molecule)
Pure Substances and Mixtures
►Study this awesome diagram.  Hover your mouse over the parts of the image.






(2) p. 8-10a, Measurements and Units; The Metric System








(3) p. 10-12a, Manipulating Units








(4) p. 12-18a, Converting Between Units

Unit Multipliers at Donna Young.

Simple, easy!  A bit loud, so you may want to turn it down.



Look at Table 1.3 on p. 15 - Relationships between English and Metric Units.
And these symbols can mean approximately equal to≈, ≃, ≅.


More practice.  =)










(5)  p. 18-21, Concentration

It matters what air we breathe!
We normally breathe about 21% oxygen in the air we breathe.  The rest that is not oxygen, but other harmless gases, we simply breathe back out along with Carbon Dioxide.
Sometimes a patient needs more, like higher concentration of 80% oxygen.



People with Chronic Obstructive Pulmonary Disorder (COPD) cannot have high concentrations of oxygen.