Test Prep and Review - Oct. 31, 2013

It seems like we've done quite a bit this week while preparing for the test on Thursday.

On it's way up.

We started Monday with a quick visit about the weather. The water barometer was the highest it has been this school year. In fact in the afternoon water was actually dripping from it. It was quite foggy this morning so I shared my Great Grandmother's old wives tale of "It will rain 100 days after a heavy fog." So we marked the calendar on 100 days out - Feb. 5. We'll see what happens.

On Tuesday students were given the study guide for the test. But first we reviewed colloids by making some samples of oobleck and goop/gak/flubber.

Oobleck ingredients - cornstarch and water.

We used the ratio of approximately 2 cornstarch to 1 water. This creates a non-Newtonian liquid that becomes solid under pressure. To see oobleck dancing watch this video.
To see it on the Ellen DeGeneres Show watch this video.
 Ingredients for goop/gak/flubber consist of water, borax and glue.

My recipe calls to make a solution of the white glue and water with a ratio of 1:1. An a borax solution (really a suspension as it settles out) at a ratio of 8:1. In this case the water is the solvent (large amount) and the borax is the solute (small amount).
We measured out equal amounts of each solution.Then combined them and stirred, creating a chemical change and producing this.  Another recipe and video is located here.  

On Wednesday we did a "Mix & Match" review of vocabulary and terms for the test. Students were given a card and they had to find all of the matches. Some only had one, others had five. It got us up, moving, and thinking.

Which one?

A correct set.

I don't think so.

Let's mix it up! Mixtures

Physically separating the iron filings using magnetism.

Using solubility to remove the salt from the sand.

On Monday we separated a mixture of salt, sand and iron filings. We used their physical properties to accomplish this.
 
First we removed the iron filings using their property of magnetism. A magnet was able to gather up most of the filings in the mixtures.








After that, we used solubility to separate the salt and sand.  We added water to the remaining mixture. This put the salt into solution, as it is soluble in water and sand is not

Filtering out the larger particles of sand from the salt water.

Removing the water from the salt.

Then we removed the sand from the water using filter paper.









And lastly, we used boiling point to separate the salt and water. Since it is lower for water, it evaporated, leaving the salt behind in the beaker.

Concentrated vs. dilute

 On Wednesday, we looked at solutions. They are homogeneous mixtures.

We looked at concentration or the amount of solute in a solution- concentrated on the left and dilute on the right.

Cold vs. hot water

Instant tea vs. tea leaves

One variable affecting rate of solubility is temperature. Obviously, hot water put the tea into solution quicker than cold water.









Another variable is particle size. Thus the powered tea goes into solution quicker than the tea leaves.

This is our Graphic Organizer as completed for Mixtures. Click to check it out.

Oct. 18, 2013 and it's snowing!

Snow collecting on door frames waiting to be installed.

Snow in the evergreens behind the school.

Yes, we had snow falling today during the afternoon classes. Students are guessing if/how it will affect the PHMS band's performance tonight at the BHS football game. Luckily, today was the day to record in our weather journals. It was interesting to see how the temperature, wind and visibility dropped during the day. 

We've been studying physical and chemical properties of matter this week. We did the Gizmo, Mystery Powder Analysis from Explore Learning. Students collected data on 5 known substances - salt, gelatin, baking soda, baking powder, and corn starch. Then they determined the identity of 5 unknown substances and 5 mixtures of two substances.

This is "WHAT?"

Registration papers for the STEM activities.

Girls have two opportunities to explore STEM careers. I posted these links at the school's Facebook page but here they are again, in case you want to check these opportunities out.
WSU's Exploring your Horizons and K-State's Grow   

   Next week we will begin working with mixtures. Lots of new vocabulary coming up!

Coming next week - mixtures, solutions, and suspensions.

Physcial and Chemical

We are still working with Physical and Chemical Properties and Changes.

We did a lab where we calculated the density of 14 different items and then analyzed the densities from least to greatest. We discovered that plant based items were the least dense, then synthetics like nylon and PVC. Those were followed by minerals and the metals were the most dense.

Create a Density Tower

Here is a fun activity that you could do at home. Link to Steve Spangler Science to watch a video on how to make one.

We also worked with changes in states of matter, using water as the substance. This gave us practice in using thermometers, recording data, and analyzing that data. Next week we will try and discover the identity of  some white mystery powders using their physical and chemical properties.

Yes, you really do need to collect data.

What was that temperature?

How do we tell if it is boiling?

Look at the condensation!

 

Cha, cha, changes......

Some of the items used in class today.

 This week we've been studying physical and chemical characteristics/properties and physical and chemical changes.

My camera is on the fritz so I don't have any pictures of the students working to share. Sorry  :-(

But we've watch a video, had bubble races between rubbing alcohol and corn syrup, (Hint: the corn syrup has a greater viscosity so the bubble moves a lot slower), soured milk, dissolved clam shells and played with baby food jars filled with blue colored water and baby oil (they are mini-wave machines that demonstrate density and solubility.) We also took a few notes and calculated the density of various cubes and objects.

Hope to see you at Parent-Teacher Conferences on Monday, Oct. 7 and Tuesday, Oct. 8 from 5:00 to 8:30 PM