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Science 09 2013-2014 Reproduction Unit | Space Unit | Electricity Unit | Chemistry Unit
=Unit 1: Chemistry=

Pure substances are pure because their properties are always the same. Why are they always the same? We can write a definite chemical formula for pure substances.
 * 2013 September 4:** Pure substances versus impure substances (**//Classifying Matter://** Textbook page 126)

Not pure substances have properties that vary because we can't write a definite chemical formula for them. For example, we add salt to water when cooking to raise the boiling point. The boiling point change depends on how much salt there is in the water. We salt roads in the winter to lower the freezing point of water. How much the freezing point drops depends on how much salt is used.

We use the term chemical to describe any matter.

We ended the class by introducing WHMIS. This is a safety protocol for hazardous chemicals in the workplace. A major component of WHMIS is labelling of chemicals, MSDS (information sheets) and education about safe handling of hazardous materials.

Today, we looked at some materials from the [|Perimeter Institute of Physics]. We looked at page 11 of this handout first to practice drawing an inference (conclusion) from some observations.
 * 2013 September 5:** Processes of Science

Share your story about the picture below of the two sets of animal tracks by clicking on [|this link].(right click on the link to open it in a new tab). A summary of responses can be found [|here]. Next we saw three short videos in the Alice and Bob series and worked on page 13 of this handout:


 * [|How can atoms exist?]
 * [|Why is it dark at night?]
 * [|Where does my energy come from?]

If you would like to share your observations and inferences from the above videos, [|click here]. To view responses shared so far, [|click here].

We ended the class by viewing the video [|The Poetry of Reality]. Main point: it's OK to not know the answer. Let's develop our skills to learn the process of science.


 * 2013 September 8**: Atoms (textbook page 151-156), [|Chemical Change, Physical Change] (Textbook page 131-137)

A large part of this unit looks at models of the atom. We will view a video about atoms today.

At the end of the video, it mentions organic chemistry. Note that most organic chemicals ARE NOT from living things. A special group of organic chemicals are [|hydrocarbons] and their derivatives (containing C, H, O). The burning of hydrocarbons releases carbon dioxide and water:

hydrocarbon + oxygen --> carbon dioxide + water natural gas + oxygen --> carbon dioxide + water (this is what your furnace and hot water heater does) gasoline + oxygen --> carbon dioxide + water (this is what your vehicle does)

(in order to burn something, you need oxygen, that's why we have oxygen on the left side of the arrow)

We should also be able to [|tell the difference] between a //physical change// and a //[|chemical change]//. Basically, if there is a chemical reaction (a change in the chemicals before and after some event), you have a chemical change. Physical changes include change of state (liquid to solid - freezing, liquid to gas - evaporating), grinding, cutting, chopping, expanding due to heating etc. Although indicators of chemical change are used to infer that a chemical change has occurred, they can sometimes indicate a physical change as well. For example, bubbling in a liquid might be due to boiling (a change of state) rather than a new gas forming during a chemical reaction. We also use the terms [|physical property and chemical property]to describe matter. Most properties of matter are physical properties (Table page 134-135). Chemical properties deal with how a specific chemical reacts with other chemicals.

Do page 141 #1-5. Don't forget the table of physical properties on page 134-135.

Use your textbook and the two web pages attached to answer the WHMIS worksheet. See also page 435 of your textbook.
 * 2013 September 11: WHIMIS**

One of the properties I noted today was that water has a //density// of 1 g/mL. This means that 1 L of water has a mass of 1 kg. This also tells you that anything that floats in water has a density <1 g/mL and anything that sinks in water has a density > 1 g/mL.

Prepare for the lab next Monday (read page 142-143) and note the material given below: No new chemical is formed with this type of change. || **Chemical Change** The chemicals you have after the change are different from the chemicals you have before the change. || grinding ripping change of state oxidising tarnishing rusting explosion combusting
 * **Physical Change**
 * chopping
 * boiling
 * condensing
 * evaporating
 * freezing
 * melting || burning

Indicators of chemical change include: Because we don't have sodium carbonate (Na 2 CO 3 ) and lead compounds are quite toxic, we will make the following substitutions [|:]
 * heat released
 * light given off
 * new smell
 * change of colour
 * bubbling (new gas forming) ||

Test 1: baking soda (NaHCO 3 ) and vinegar Test 2: sugar and heat (unchanged) Test 3: copper (II) sulphate and barium chloride Test 4: copper (II) sulphate and water (unchanged)

Jazz is cancelled this Monday (Sept 16) and will start the following Monday (Sept 23).

Here is the grading rubrick we will use. Here is what we covered on Wednesday for the lab writeup ([|sample lab writeup])
 * 2013 September 16 & 18:** We did the lab on page 142-143 on Monday and then talked about how it will be written up and graded on Wednesday. Don't forget to the use the information presented above when you write up your lab.


 * 2013 September 23:** Formation of a [|precipitate] - evidence of chemical change:

Take a look at test 3 (barium chloride solution + copper (II) sulphate solution) media type="custom" key="23886188"

Compare this to lead nitrate (clear solution) + potassium iodide (clear solution) forming lead iodide precipitate (yellow solid) media type="custom" key="23886190"

When two solutions are mixed and a solid forms (called a precipitate), you know that a chemical change has occurred.

The grading chart for the Atomic Models Comic Life Refer to pages 152-513 and 156 (timeline). Make sure you save the links you used in your research. Use images from [|Britannnica Images].
 * 2013 Sept 23 & 25:** Bohr Diagrams and Atomic Models Comic Life

We also learned how to draw Bohr diagrams (page 186). The Bohr diagrams in the textbook do not have the details of the nucleus (number of protons and number of neutrons) which you require.

Extra notes if you need them.

media type="custom" key="23919438"

Continue to work on your Models of the Atom (students using computers) and Bohr Diagrams. We will introduce Periodic Law today. Do the following looking at your periodic table at the back of your text:
 * 2013 September 26**: Models of the Atom, Bohr Diagrams, Periodic Law Intro
 * What patterns do you see in the physical properties of elements as you go across a row (called periods). Physical properties are on page 134-135. For example, where are the metals and where are the non-metals. Where are the solids, where are the liquids, where are the gases?
 * What patterns do you see as you move down a column (called columns)
 * What do you notice about the electron arrangements for the first 18 elements as you move across a row (see page 186)
 * What do you notice about the electron arrangements for the first 18 elements as you move down a column (see page 186)

Continuing from last Wednesday's work, we should now be able to notice some patterns from your answers to the 4 bulleted items above:
 * 2013 September 30:** Periodic Law & Physical/Chemical Changes lab (returned to students, last day for lates on this lab)

You are given a set of 20 'cards' with an element on each card. The first thing you must do is number the cards from 1 to 20 with #1 being the element with the smallest mass and #20 the element with the biggest mass (USE A PENCIL!). You will use these cards to practice arranging them in a logical sequence by following these basic steps.
 * 1) Starting with the #1 (smallest mass), place it on the table. Continue to place higher numbered cards to the right of #1 until you get to a noble gas (inert gas).
 * 2) Inert gases are ALWAYS found at the right most column of the periodic table. Once you have placed an inert gas in a row, it signals that you must start a new row.
 * 3) As you place the cards sequentially from left to right, you should notice that soft, silvery metals are in the first column, followed by metals, metalloids, non-metal solids, non-metal gas and finally inert gas.
 * 4) If you are working with fewer cards, there may be a large gap between the two elements. You should be able to reason whether the card belongs in the same row or the next row based on the patterns in step 3 for a complete row of elements.

After you have arranged all 20 cards, try to randomly choose any 10 of the 20 cards and see if you can place the 10 cards properly in a periodic table. You will be given a question similar to this on the unit test at the end of October.

On Wednesday, we will be in the LRC where you can work on the Comic Life Atomic Models assignment.


 * 2013 October 7:** You may hand in your lab for regrading if you handed it in on time last Monday. We will continue on with Periodic Law today. I have booked the LRC for October 17th to finish up the Atomic Models Comic Life. [|Click here] for some answers to the periodic law activity.

The due date for the Atomic Models Comic Life is October 21 (Monday). There will only be one hand-in opportunity for this because you have been given time to peer evaluate your work prior to the final due date. You have one last class (Oct 17) to work on this assignment.
 * 2013 October 9:**

We went over the Periodic Law (20 cards of elements) today. I asked you to take 10 of the 20 cards and try to arrange them as a periodic table WITHOUT using your textbook. This will be a CLOSED BOOK question on the unit test. The unit test will be at the end of October / beginning of November. Here are [|the answers]. You can keep practising by using any 10 of the 20 cards and arranging them in a periodic table. You can write down your answer and have me check it if you wish.


 * 2013 October 16:** Experimental design and chemical properties. One of the learning targets we need to work on (based upon the grading of the lab) is the distinction between chemical property (pg 136 Table 4.2) versus physical property (pg 134-135). //A chemical property is basically how one chemical will react with another chemical.// Virtually anything else is a physical property. To better understand this, we will look at how to design an experiment to investigate the chemical properties of baking soda. [|Click here] for the Google Doc that was shown in class today.


 * 2013 October 17:** Go directly to the LRC to work on your Comic Life assignment (due October 21 ).


 * 2013 October 21:** Review attached

Classifying Household Chemicals Chem Review Page 1 chart answers You will get a copy of these answers for textbook questions on Nov 5
 * 2013 October 30 Answers:**