### Archive of ‘Science9’ category

For our final unit you will be investigating waves in a series of activities and experiments. You will complete one experiment for Criterion C.

There is a final exhibition in the second week of June, and you will contribute to this on an area of sight or hearing. The reflection on your learning will be your final criterion D task.

Here is a unit overview.

Waves in general:

Wave activity with simulation on Phet

Wave properties practice problems

Solutions to wave properties practice

Sound:

How to measure speed of sound in two ways – one outside and one with a tube and cylinder

Free software to find frequency of sounds (use audioxplorer) and helpsheet about it

Problem to solve using speed of sound, and some more problems and the answers

Light

See the text book pg 86-7 for reflection in mirrors, 88-9 for refraction and 90-1 for internal reflection.

1 – Tracing rays through a block using pins – complete the sheet and then take two similar measurements with a block and pins.

2 – Refraction and a coin in water – students should complete the sheet then set up the investigation described

3 – Refraction and a displaced ray. Complete the sheet and then collect three measurements using a ray box and analyse.

4- Angles in a simulated lab – open the PheT simulation. Use the simulation to see what happens in the following situations

i – the refractive index of the top material is less than the bottom one (i.e. air on the top and water on the bottom)

ii – the refractive index of the top material is greater than the bottom one (i.e. water on the top and air on the bottom)

iii – the refractive indexes of the materials are the same

We have looked at a video on collision theory and some examples of how to monitor reactions. The simulation to investigate reaction rates also allows you to picture what is happening at a molecular level.

You may wish to read the section on kinetics in your text book as well.  In particular I would recommend section 8.05 for explaining collision theory.

Here is your assessment task on kinetics: you need to design and do an experiment to look at a factor that affects reaction rates. You should complete collecting data for this on Thursday April 16th. You should complete the report Monday during class and hand it in before class on Thursday April 23.

Finished your experiment? Kinetics review questions are here. I also recommend the questions in the section on kinetics in the text book as well. (link)

You have a cumulative test coming soon. If you would like to get started on review (who wouldn’t?), a study guide is here.

Your test is on Monday March 16, and you got a review package in class with some practice questions.

Here is another document that might help you structure your review. It gives all the objectives for this unit, and the major lines of inquiry. Check that you can respond to each objective.

Charles Darwin, Alfred Russell Wallace and their theory of Natural Selection:

Charles Darwin and Alfred Russell Wallace both discovered the process of natural selection independently, Darwin in 1837 and Wallace in 1858 as this 30 minute video shows.

Speciation:

Speciation is the formation of two species from one species.  Describe an example of speciation from one of our examples: Galapagos finches, giraffes or lizards.

Dogs, Wolves and Selective Breeding:

Where did dogs come from?  It is universally accepted by scientists that dogs came from wolves.  But were they selectively bred by humans or did they evolve from wolves into dogs?  These are  two competing hypotheses proposed by different scientists.  You will watch a video that presents the arguments.  You decide which is the best answer.

Here is an article about wolves, dogs and their diet and digestion.

Here is a model you can use to explain how Natural Selection works.

How does selective breeding of dogs help humans?

Has the selective breeding of dogs gone too far? Dogs That Changed the World, Part 2.  You will answer that question through a Criterion D assignment.  TSC here.

For this project you will need to choose a breed of dog as your main example. Find lists of breeds of:

working dogs  such as Herding dogs  or Guard dogs (scroll down to the bottom)  also hunting dogs or companion dogs, or just all dogs with a picture.  Very obscure breeds or ones without a clear purpose may be very hard to research well.

Once you choose a dog breed to focus on, please note your choice here. It would be best if everyone had a different breed of dog as their main choice.

Suggested timeline:

Feb 27 watch video on evolution of dogs from wolves (part 1) and take notes to answer question 1 (finish for HW)

Monday, March 2 watch dog video part 2 on selective breeding of dogs and take notes to answer section 3. Start research on chosen breed of dog for section 2.

We do not have class on Thursday March 5 but you could spend some time finishing your research during the entire week between classes.

Monday March 9 Complete section 4 and write the essay using your notes. Check your sources are in MLA format.

Thursday March 12 Turn completed essay in using Turnitin.com at start of class.

Here is the link to the TSC for this experiment.

The design for the experiment will be assessed on Monday. Please have it printed.

Use some background research to support your hypothesis.

One site that may be useful about surface tension of water is here. Here is another about salt dissolving in water. There is a link on the left of that second link about sugar as well. What ever you use, please cite in MLA format.

Building molecules

1. Go to the Phet simulation Build a molecule and see how molecules are attached and what the rules are for formulae.
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 Click to Run

(HInt : you will likely get a message that says it was blocked from running… go to the apple (top left) and click Preferences >Security and privacy > Open Anyway. Unless you have a lot of time, choose Update Java LATER)

Write down a few sentences and maybe a diagram or two to show what you discover.

2. Get a model building kit for your table.

Follow the instructions from the handouts at the front of the room to build molecules with the kits. Record what you make, and the shapes formed.

3. What are the similarities and differences between the models (online and plastic)?

Which is clearer? Why?

This unit is a chemistry based topic.
We can understand how substances behave by knowing how they are held together. Atoms are held together with bonds. There are three main types of bonds we will look at: Ionic, Covalent, and Metallic.

What are atoms, what are they made and how can we rearrange parts of them so they can make connections?
Here is a simulation from pHet: Build an Atom You will need to download and run it.

Here is an overview of ionic bonding from the BBC. Here is a video if you prefer to listen.

Practice naming ionic compounds (can click only “binary compounds” to start) http://chemsite.lsrhs.net/FlashMedia/html/compoundsAll.html

For later in the unit:
Here is the overview of covalent bonds. Also there is a video/interactive clip about covalent bonding here.