Changes in Matter unit

Here is a list of the objectives that we covered in the third unit. You are expected to be able to:

  • Balance chemical equations (covered in the test before the break)
  • Explain the law of conservation of mass during a chemical reaction
  • Represent the conservation of mass using the particle model
  • Determine the quantities of reactants or products using stoichiometric calculations (gram or mole) (covered in the test before the break)
  • Distinguish an endothermic reaction from an exothermic reaction (for example, how does if change temperature? where is it in the chemical equation?)
  • Describe what a precipitation reaction looks like
  • Represent a precipitation reaction using the particle model
  • Associate known chemical reactions with decomposition or synthesis reactions (for example, cellular respiration and photosynthesis)
  • Represent the photosynthesis reaction in a balanced equation
  • Represent the respiration reaction in a balanced equation
  • Give examples of acid-base neutralization reactions
  • Name the products formed during acid-base neutralization (salt and water)
  • Recognize an acid-base neutralization from its equation
  • Determine the molecular formula of the salt produced by the neutralization of a given acid and a given base


Molecules & Solutions

Here is a list of the objectives that we covered in the second unit. You are expected to be able to:

  • Define the concept of solubility
  • Describe the effect of variations in temperature on the solubility of a substance – DONE IN SOLUBILITY LAB
  • Determine the concentration of an aqueous solution (g/L, percentage, ppm, mol/L)
  • Define the concept of electrolyte
  • Qualitatively speaking, associates the strength of an electrolyte with its degree of dissociation
  • Describes the mechanism that allows aqueous solutions to conduct electricity (electrolytic dissolution of a solute, formation of mobile ions)
  • Describes the pH scale (acidity, alkalinity, neutrality, increasing and decreasing values)
  • Determines the pH of a few common substances (e.g. distilled water, rainwater, saliva, lemon juice, cleaners) – DONE IN pH LAB
  • Defines the concept of ion
  • Explains dissolution using the particle model
  • Explains dilution in terms of concentration and volume
  • Determines the final volume or concentration of an aqueous solution after dilution (e.g. the concentration of a solution decreases by half when the volume of solvent is doubled)
  • Defines a covalent bond as a bond resulting from a sharing of electrons
  • Makes a schematic representation of a covalent bond
  • Identifies molecules that feature a covalent bond (e.g. N2, CO2)
  • Defines an ionic bond as a bond resulting from the gain or loss of electrons
  • Makes a schematic representation of an ionic bond
  • Identifies molecules that present an ionic bond (e.g. NaCl, NH4OH)
  • Associates an ionic bond with an electrolytic substance
  • Applies nomenclature and notation rules to name the molecule or write the molecular formula of binary compounds
  • Recognizes the common polyatomic ions (e.g. NH4 , OH , NO3, CO3 , SO4 , PO4 ) by their name, their formula or their composition

Wow…that is quite a list! You can use this as a checklist while you are studying. We will be focussing on the ones in red for next week’s test.

I’ve put together a practice test (Sakai Resources > Classwork > Molecules and Solutions. Please use the Practice Test VoiceThread (see the VoiceThread menu in Sakai) to share your answers with others or to ask questions as they come up. I will post the answer key on Wednesday.



#SciStuChat – Surviving a year in space

Every month, there is a #SciStuChat Twitter chat for students all over the North America to communicate with scientists on a different theme. In October, the theme is “Surviving a year in space” and the chat will be Thursday (October 8) from 9-10PM:

Astronaut Scott Kelly is spending a year in space on the International Space Station, and his Russian counterpart cosmonaut Mikhail Kornienko is doing the same thing. On Sept 15 they reached the halfway point of the#yearinspace. The major purpose of the #yearinspace is to learn the demands the human body requires to make the trip to Mars. 

You can find more information here. Since most of you have not participated in a Twitter chat before, I put a few tips together. This is an optional activity, but I recommend it. You will have the opportunity to ask real scientists questions!

If you want to see tweets during the chat

  1. Go to
  2. Under the #SciStuChat banner, select “Live”
  3. As new tweets come in, you will be notified at the top of the page

If you want to participate

  • Click on the Log-in link in the top right corner and enter your username and password.
  • To tweet, click on the Tweet button in the top right corner of the window. Don’t forget to add the #SciStuChat hashtag every time!
  • Use the Q & A format.
    question and answer
  • To respond to someone else’s tweet, use one of the buttons below their tweet:


I will be following along with you! Good luck!