Tuesday, October 26, 2004

Electricity - Lesson 1

Here's the Electricity Concepts we Covered for our First Class in Electricity:


Static Electricity

To understand what static electricity is, we have to learn a little bit about the nature of matter. Or in other words, what is all the stuff around us made of?


EVERYTHING IS MADE OF ATOMS


Imagine a pure gold ring. Divide it in half and give one of the halves away. Keep dividing and dividing and dividing. Soon you will have a piece so small you will not be able to see it without a microscope. It may be very, very small, but it is still a piece of gold. If you could keep dividing it into smaller and smaller pieces, you would finally get to the smallest piece of gold possible. It is called an atom. If you divided it into smaller pieces, it would no longer be gold.


ELECTRONS CAN MOVE

The protons and neutrons in the nucleus are held together very tightly. Normally the nucleus does not change. But some of the outer electrons are held very loosely. They can move from one atom to another. An atom that looses electrons has more positive charges (protons) than negative charges (electrons). It is positively charged. An atom that gains electrons has more negative than positive particles. It has a negative charge. A charged atom is called an "ion."


Some materials hold their electrons very tightly. Electrons do not move through them very well. These things are called insulators. Plastic, cloth, glass and dry air are good insulators. Other materials have some loosely held electrons, which move through them very easily. These are called conductors. Most metals are good conductors.


OPPOSITES ATTRACT

Now, positive and negative charges behave in interesting ways. Did you ever hear the saying that opposites attract? Well, it's true. Two things with opposite, or different charges (a positive and a negative) will attract, or pull towards each other. Things with the same charge (two positives or two negatives) will repel, or push away from each other.

A charged object will also attract something that is neutral. Think about how you can make a balloon stick to the wall. If you charge a balloon by rubbing it on your hair, it picks up extra electrons and has a negative charge.

To learn more go to the following websites:

http://www.sciencemadesimple.com/static.html

This website is like a video/slideshow to help show how opposites attract and like charges repel.
http://chemmovies.unl.edu/Chemistry/DoChem/DoChem025.html

hwk
pg. 52, 53 C.P.

Friday, October 15, 2004

Lesson 18 - Unit Review

The Periodic Table

Mendeleev, Dmitri
(1834-1907): Russian chemist born at Tobolsk, Siberia.

He studied science at St. Petersburg and graduated in 1856.

In 1863 he was appointed to a professorship and in 1866 he succeeded to the Chair in the University.

Mendeleev is best known for his work on the periodic table; arranging the 63 known elements into a Periodic Table based on Atomic Mass!

Moseley, Henry (1887-1915):

A British chemist who studied under Rutherford and brilliantly developed the application of X-ray spectra to study atomic structure

His discoveries resulted in a more accurate positioning of elements in the Periodic Table by closer determination of atomic numbers.

Our Current Periodic Table

Go to this address to have a little practice with your elements, periods, and families.

Good luck studying this weekend!
http://www.chemicalelements.com/


Remember to complete your review sheet and Homework.

Here is another review sheet for you if you want more practice courtisy of Morrow Galpern (an excellent resource for all you parents out there looking for lessons for Grade 9 Science www.morrowgalpern.ca

Below is the review for the unit.
http://www.morrowgalpern.ca/snc1d/snc1d_u3r.doc

Thursday, October 14, 2004

Lesson 17

Isotopes, Periodic Table

Atoms of the same element can have different numbers of neutrons; the different possible versions of each element are called isotopes. For example, the most common isotope of hydrogen has no neutrons at all; there's also a hydrogen isotope called deuterium, with one neutron, and another, tritium, with two neutrons.
You can find more about isotopes on the following website:

http://www.colorado.edu/physics/2000/isotopes/


Periodic Table - Division of Metals and Nonmetals

Metals, Nonmetals, & Metalloids
- Ionic Compounds
Most periodic tables contain a stairstep line which allows you to identify which elements are metals, nonmetals, and metalloids. Following are descriptions of each of the three types of materials.


Metals


Most elements are metals. 88 elements to the left of the stairstep line are metals or metal like elements.


Physical Properties of Metals:
Luster (shininess)
Good conductors of heat and electricity
High density (heavy for their size)
High melting point
Ductile (most metals can be drawn out into thin wires)
Malleable (most metals can be hammered into thin sheets)
Chemical Properties of Metals:
Easily lose electrons
Corrode easily. Corrosion is a gradual wearing away. (Example: silver tarnishing and iron rusting)


Nonmetals
Nonmetals are found to the right of the stairstep line. Their characteristics are opposite those of metals.


Physical Properties of Nonmetals:
No luster (dull appearance)
Poor conductor of heat and electricity
Brittle (breaks easily)
Not ductile
Not malleable
Low density
Low melting point

Chemical Properties of Nonmetals:

Tend to gain electrons

IONIC COMPOUNDS:
Since metals tend to lose electrons and nonmetals tend to gain electrons, metals and nonmetals like to form compounds with each other. These compounds are called ionic compounds.

When two or more nonmetals bond with each other, they form a covalent compound.


Metalloids
Elements on both sides of the zigzag line have properties of both metals and nonmetals. These elements are called metalloids.


Physical Properties of Metalloids:
Solids
Can be shiny or dull
Ductile
Malleable
Conduct heat and electricity better than nonmetals but not as well as metals

Find out more about metals, nonmetals and ionic compounds at:
http://web.buddyproject.org/web017/web017/metals.html

Homework:

pg. 97 #1-3, Text
pg. 28,29,34 Course Pack
Gold Dust Kid Story

Tuesday, October 12, 2004

Lesson 16

Combining Capacity and Word Equations

Combining Capacity

The combining capacity is the amount of electrons (cars in the garage) an atom needs to make it a stable octet (eight electrons on it's outer shell - this is different for hydrogen)

Word Equations

The left side of the chemical reactions are the "reactants" whereas the right side are the "products"
The following website "sums up" all of the information I have on word equations - http://www.nelsonthornes.com/secondary/science/scinet/scinet/reaction/collis/word.htm

Homework:
pg. 42 and 43 course pack


Sunday, October 10, 2004

Lesson 15 and Review

ATOMS, ELEMENTS, BOHR-RUTHERFORD DIAGRAMS AND REVIEW

Atoms:
We are currently investigating the properties of ATOMS and subatomic particles (protons, neutrons and electrons)

Recall that the basic particle discussed earlier in the unit was the atom. Look at your "Introduction to Atomic Particles note-taking sheet" that we did on the overhead in class.

Bohr-Rutherford Diagram
Reveiw information about protons, neutrons, electrons, and their arrangement around the nucleus using a Bohr-Rutherford style diagram.

Elements
Elements are substances containing atoms of only one type. The periodic table is numbered from left to right and divided into families sharing similar charges.

Families
We noted that the Alkali Metal family all have 1 electron on their outer shell. The other families have the same rule, THEY ALL HAVE THE SAME NUMBER OF ELECTRONS ON THEIR OUTER SHELL.

Atomic Number and Atomic Mass
Recall, that the Atomic number is the number of subatomic positive particles in the nucleus.
The atomic Mass is the combination of the subatomic neutrons plus the protons all in the nucleus. This gives the element it's weight.

Electrons
Electrons are negatively charge subatomic particles which, according to the bohr-rutherford model, orbit around the nucleus.

Standard Atomic Notation

The universal way to record the atomic mass and atomic number as well as the chemical symbol is:
http://hyperphysics.phy-astr.gsu.edu/hbase/nuclear/nucnot.html


Subatomic Particles Mass
Protons and Neutrons have the same mass of 1 atomic unit. Whereas, electrons have a mass of 1/2000 atomic units. Obviously, the electrons wt. is significantly less than the protons and neutrons and is therefore not really a factor in the Atomic Mass.

Review Topics

All of the above is what you will be tested on plus...

1. Properties of the Atom

2. Bohr-Rutherford Diagrams

3. History of Atomic research (handout from textbook pg. 82)

4. Combining Capacity of Carbon, Hydrogen, Oxygen, and Nitrogen ( model building activity from Friday's class - eg. Hydrogen has a combining capacity of 1 because it had only one space)

5. Electrolysis - How does it work? Which gas is "broken away" faster oxygen or hydrogen? How do you test for oxygen? How do you test for hydrogen? Word Equation for the electrolysis lab ___electricity
Water ------->Hydrogen and Oxygen

To procrastinate I have provided a great game and it's all about science. Check it out - I almost made it to the end let's see how well you guys do...
http://education.jlab.org/million/index.html

Have a wonderful long weekend and good luck studying.

Mr. Doctorow



Wednesday, October 06, 2004

Lesson 14

The Atom, Standard Atomic Notation, Bohr-Rutherford Diagrams.

Okay it sounds like a lot of information but that's only because it is...

Sorry.

The Atom

Dalton's Atomic Model - text pg. 84 (this information was taken directly out of Nelson Science 9 pg. 84)
- "All matter is made of atoms which are particles too small to see
- Each element has it's own type of atom with it's own particular mass
- Atoms cannot be created or destroyed or [broken up] in chemical changes"

Michael Faraday - Ions - text pg. 84
- "discovered that some atoms gain electrons and some loose electrons during chemical reactions
- matter must contain a positive and negative charge
- opposite charges attract and similar charges repel
- Atoms combine to form molecules because of electrical attractions between atoms"

J.J. Thompson - Subatomic Particles
- Discovery of the electron and proton and neutron

Ernest Rutherford - Nuclear Model
- Electrons are positioned in the "outer orbit" of the atom and are always moving
- Protons and neutrons are in the core or nucleus of the atom (nucleus - hence nuclear model)

Standard Atomic Notation pg. 88 text

When writing the standard atomic notation of the Atom you write the following

35 <---------------------- Mass Number
CL<---------------------- Chemical Symbol
17 <---------------------- Atomic Number

Bohr-Rutherford Diagrams pg. 92 Text

Bohr (planetary) diagrams DO NOT have the number of protons and neutrons listed in the nucleus
- with heat, energy or light the electrons in the outer shell are in an excited state! These electrons are ready to jump to another atom.
- Ground state is when the electrons are in a low energy state ( a full octet). The outer orbit has either 2 electrons (first orbit) or 8 electrons (subsequent outer orbits)


Bohr-Rutherford diagrams DO have the number of protons and neutrons listed in the nucleus.

Here's a practice sheet for you. I have also handed this out in class but if you lost it... here it is.

http://www.morrowgalpern.ca/snc1d/snc1d_brd.doc

Here's a website for you to practice your elements:
http://www.quia.com/mc/3.html

Homework

Complete bohr-rutherford diagrams
Course pack pg. 37
Write out standard atomic notation for first 10 elements.
Colour families course pack pg. 31
** This should not take you more than about 30 min. to complete all of this assigned work. This material will be on Tuesday's quiz along with elements, compounds, and counting atoms.






Lesson 13

Library Research

After signing up today for your project be sure to continue to synthesize your information using your assignment sheet as your guide.

Next class, we will be taking up work on the histroy of the atomic theories that you are to complete for homework (worksheet fromt the beginning of class).

We will then be exploring the bohr-rutherford model of the atom and building atomic structures.

Then we will be looking to learn some simple word equations and how to count atoms in an equation.

Keep in mind the unit test is on October 15. Please use this website as a resource to post concerns, questions or comments under the "comment" section of the web page.

Cheers,
Mr. D

Tuesday, October 05, 2004

Lesson 12

BREAKING COMPOUNDS INTO ELEMENTS

Today's lab involved two types of experiments but both had the same objective. We split a compound into it's basic elements.

With the first demonstration we used electrolysis to break down H2O:
Our Findings -
- the negative current picked up the hydrogen gas and split it twice as fast as the positive current split the oxygen gas.
- there were twice as many hydrogens as oxygens as well.

Then we tried to split H2SO4 (sulphuric acid) to see if we could isolate the hydrogen gas and get it to make a massive "pop".

We did it alright!!!

So, we determined that compounds can be split into their basic elements.
Homework:

Complete the lab question #11 from the electroylsis lab
Pick your element for your STSE assignment
Read pg. 64 and answer questions #1-4




Friday, October 01, 2004

Quiz Review * Revised

Here is the homework assignment relating to uses for metals and non-metals. By all

means use the internet as your resource. Make sure that any information that you

use is put in YOUR OWN WORDS.

Uses for Metals and Non Metals

Make a chart to determine all of the possible uses you can think of for non-metals and metals include at least 10 items in your chart.

Uses______________Metals____________Non-metals

Heating food______Stainless steel___________none

Quiz Topics

Here is a review for your quiz on Monday.

1. Read your notes carefully to help you study and don't be shy about posting your questions on the site if you need help.

2. Particle Theory of Matter to explain states of matter (solid, liquid and, gas)

3. Definitions (heterogeneous, homogenous, phase, alloy, element, compound, mixture, pure substance etc...)

4. Testing for gasses (oxygen, hydrogen and carbon dioxide). Know the different test to determine what type of gas is present

5. Classifying Elements (properties of metals vs. nonmetals). Know the lab and results from the lab.

Try the following website to give yourself a little practice for the periodic table. You all will be awesome be the time we get to the table of periods...
http://www.creative-chemistry.org.uk/funstuff/jigsaw/table.htm

GOOD LUCK AND HAVE A GREAT WEEKEND!!!

Community Involvement Hours

Here are the guidelines for your community involvement hours:

1. All eligble activities are in your booklet.
2. You may find your own voluynteer placement but Opportunities are posted on the volunteer board outside room 216.

3. Once you have a placement you are asked to pick up a completion form in guidance.

4. When you are done submit your form to guidance with your supervisors signature, parents signature and your signature.

5. Guidance will keep the white copy and you keep the yellow.

6. A total of 40 hours is necessary by the time you graduate.

Now get busy!!!