Grade 7 Science and Math

Please refer to students' agenda.

Math Project due :Dec. 17th, Monday.

Please make sure that your science and math duotangs are nicely organized.
If not, I will not be marking any of your homeworks and tests in your duotang.

Grade 10 Science

More example questions on Energy Efficiency:

With the price of fuel constantly on the rise, builders of jet engines are trying to develop more energy-efficient models. The first jet turbine engines had an energy efficiency of 22 percent. Engineers have proposed a model with a thrust capacity of 40 000 N at a speed of 250 m/s. Under these conditions, the airplane uses 6.0  10⁸ J of energy a minute. At the same time, the jet turbine engine consumes 52.5 kg of fuel capable of providing 4.4  10⁷ J/kg of energy on combustion. Is the energy efficiency of this engine better than that of the older models? Show your calculations.

Answer

For one minute of flight,
Useful NRG: 6.0 x 10 J
Consumed NRG: 4.4 x 10 J/kg x 52.5 kg = 2.31 x 10 J

Energy Efficiency = Amount of Useful NRG x 100
                               Amout of consumed NRG

Energy Efficiency= 6. 0 x 10 J  x 100
                            2.31 x 10 J

= 25.9 %

Grade 7

Science

Science Presentation Due: December 5th (but you will be presenting in class in 6th)
on December 5th, I need your assignment sheet back for marking as well as other media/ posters
so I could get prepare for your presentation on following day.

Science Friday Quiz: This week's quiz will be based on whatever we learned so far (elements, mixture, solution, compounds, organic compounds and inorganic compounds).
6 Questions Total.


Math

If you still haven't correct your mistakes on Chapter 2 Test, Please do so.
Homework: Workbook P.39 Q. 1 and 2
Math Thursday Quiz: Will be on cartesian plane

Math making Games assignment Due: December 15th.
Please bring your stuff on Thursday. We will be working on making the games in class.

If you have questions, Please email me at

ekim039@gmail.com

Grade 10 Adventurers

Today, we saw an elephant toothpaste lab demo.
it was cool eh? :)

If you want, you could do a little version of the demo at home!
instead of using higher concentrated (30%) hydrogen peroxide and KI, you could get 3% hydrogen peroxide and yeast! :)

see below.

and we will be going over the chemical equation of the lab demo tommorrow!

• empty 20-oz plastic bottle (or other container)
• 3% hydrogen peroxide solution (available at nearly any store)
• packet of active yeast (from the grocery store)
• liquid dishwashing detergent (such as Dawn™)
• warm water
• food coloring (optional, but it looks nice)

Make Elephant Toothpaste

1. Pour 1/2 cup hydrogen peroxide solution, 1/4 cup dishwashing soap, and a few drops of food coloring into the bottle. Swish the bottle around to mix the ingredients. Set the bottle in a sink or outdoors or some other place where you won't mind getting wet foam everywhere.
2. In a separate container, mix a packet of active yeast with a little warm water. Give the yeast about 5 minutes to activate before proceeding to the next step.
3. When you are ready to do the demo, pour the yeast mixture into the bottle.

How It Works Hydrogen peroxide (H₂O₂) is a reactive molecule that readily decomposes into water (H₂O) and oxygen:

2H₂O₂ → 2H₂O + O₂(g)

In this demonstration, yeast catalyzes the decomposition so that it proceeds much more rapidly than normal. The dishwashing detergent captures the oxygen that is released, making foam. Food coloring can color the film of the bubbles so that you get colored foam. In addition to being a nice example of a decomposition reaction and a catalyzed reaction, the elephant toothpaste demo is exothermic, so heat is produced

Grade 7 Edible Cell Presentation

Sorry My Grade 7s!
I am finally uploading some pictures from the presentation.
more pictures will be uploaded (from Mr.Wong's camera) sometimes nextweek! :)

 Mathew's Edible Cell

 Zeid's edible cell

 Sahat's Edible cell

 Giri's Edible Cell

 Zayd's Edible Cell

 Razan's Edible Cell

 Arta's Edible Cell

 Warren's Edible Cell

 KuuKua's Edible Cell

Great Job Again!
I am looking forward to hear your presentation on December 5th!

Grade 10/ 11 Science Chapter 4 Review

ST

Chapter summaries

CHAPTER 4

Chapter summaries

C

hanges in matter

1 what are changes in matter?

• A physical change alters neither the nature nor the characteristic properties of matter. The atoms and molecules of the substance do not change (p. 108).

• A chemical change alters the nature and characteristic properties of matter. The bonds between atoms are rearranged, and new molecules are formed (p. 108).

• In a nuclear transformation, the particles making up an atomic nucleus are rearranged, and new elements are formed (p. 108).

2 CHEMICAL CHANGES

• Chemical changes are also called chemical reactions (p. 109).

• The law of conservation of mass states that the total mass of reactants is always equal to the total mass of products (p. 111).

• Balancing a chemical equation consists in placing a coefficient before each reactant and product so that the number of atoms of each element on the reactant side is equal to the number of atoms of each element on the product side (p. 111).

• Acid-base neutralization is a chemical change involving the reaction of an acid with a base, producing a salt and water (p. 119).

• Combustion is a form of oxidation that releases a large amount of energy (p. 122).

• Cellular respiration is a chemical change in which glucose and oxygen are used to generate energy. The reaction also produces carbon dioxide and water (p. 123).

• Photosynthesis is a chemical change that produces glucose and oxygen from solar energy, carbon dioxide and water (p. 124).

Grade 7

Math
Chapter test 2 will be marked and given to students tommorrow, (wendesday)
No homework

Science
Homework: Read P.70-72
Science Quiz on Thursday this week.

Science assignment: Students have to choose their topic and partner (if they decide to work alone, that is fine as well) by Wendesday.
Science Presentation Assignment Due :November 30th.

Grade 11

Support activities – Concept review

MW4

P

answer key

Concept review: chemical change,
conservation of matter,
decomposition and synthesis,
dissolution, oxidation,
photosynthesis and respiration,
physical change,
precipitation

hysical and chemical changes

1. Complete the sentences, using the words in the box below. You may not need some words, and you may use others more than once.

• always • atoms • chemical • chlorophyll • colour

• combustion • element • energy • gas • matter

• molecule(s) • nature • often • oxygen • solid

• solute • solvent • substance(s) • sugars • water

nature

substance

nature

a) A physical change is a transformation that changes neither the ________________________ nor the characteristic properties of matter. No new ________________________ is produced.

substances

colour

b) A chemical change is a transformation that changes the ________________________ and characteristic properties of matter. New ________________________ are produced. The following signs indicate that a chemical change has occurred:

– There is a change in ________________________.

energy

– There is a change in temperature.

gas

– A large amount of ________________________ is released or absorbed.

solid

– A ________________________ is emitted.

– A ________________________ is formed when two liquids are mixed together.

– The change is usually irreversible.

matter

always

matter

c) According to the law of conservation of matter, in all changes, whether physical or chemical, the amount of _______________________ ________________________ remains the same.

The mass of ________________________ does not change.

solute

solvent

d) Dissolution is the process of preparing a solution by mixing a ________________________

in a ________________________.

chemical

oxygen

oxygen

e) Oxidation is a ________________________ change involving ________________________ or a substance with properties similar to those of ________________________.

molecule

atoms

molecules

atoms

f) Synthesis is the formation of a complex ____________________ from ____________________ or simpler molecules. Decomposition is the transformation of complex ________________________ into simpler molecules or into ________________________.

sugars

water

chlorophyll

combustion

g) Photosynthesis is the process by which producers use solar energy to make their food (________________________) from carbon dioxide and ________________________. This process takes place in cells that contain ________________________. Cellular respiration is the opposite reaction to photosynthesis. It is the process by which living cells produce energy through the ________________________ of complex nutrients.

solid

h) Precipitation is the formation of an insoluble, or only slightly soluble, ____________________ substance, called a precipitate. Precipitation may occur when two solutions are combined.

2. Are the following phenomena physical or chemical changes? Check the appropriate column.

		Physical change	Chemical change
a)	A burning forest		
b)	Snow melting in the spring	
c)	The moulding of plastic	
d)	Photosynthesis in plants		

3. Various signs indicate that a chemical change has occurred or is occurring. What signs could you observe in each of the following chemical changes?

Change in colour and irreversible change

a) Rust appears on an object.

Formation of a solid and irreversible change

b) When you mix vinegar with milk, a white solid forms.

3. W
   Change in temperature, release of a large amount of energy and emission of a gas
   hen you recharge a car battery, an explosive gas (hydrogen) is formed, and the battery becomes hot.

4









. The following are steps you might take in lab procedures. Check the actions that produce a chemical change.

a) You distill alcohol. 

b) You melt ice. 

c) You burn wooden splints. 

d) You mix a blue liquid with a yellow liquid, and the mixture turns green. 

e) You mix two liquids, and a precipitate forms. 

f) You mix two liquids, and the mixture gives off a large amount of heat. 