Friday, February 01, 2008

10 Science KCVI

Ask your questions here!


Anonymous said...

Wow first one! Alright, i'm having trouble with creating a Bohr Diagram of a Lithium Isotope. From what I found out, Li 6 and Li 7 are the only stable isotopes but when I go to create the diagram, there are a big difference in the number of electrons compared to the Neutrons and Protons. I confused on how to do this, can you help?

Ms.Bearse said...

We'll discuss this in class, but I'll put this up here anyway. Lithium has 3 protons always. That is important. The next thing you have found out is that lithium can be heavy with a mass of 7, or light with a mass of 6. We can then say that heavy lithium will have 4 neutrons (4+3=7), and that light lithium will have 3 neutrons (3+3=6). Lithium that is electrically neutral (that's not an ion)will always have the same number of protons and electrons. Remember protons are positive, and electrons are negative, so to have no charge the atom must have equal numbers of protons and electrons. So, since lithium always has 3 protons, an electrically neutral lithium atom (heavy or light) will also have 3 electrons. The only difference between the two isotopes is that one has one more neutron than the other.

I hope this helps.

Caitlynn said...

Would it be possible for us to discuss all the things that I missed at lunch tomorrow because I was away with strep throat.

Ms.Bearse said...

absolutely! Come find me at the math office at lunch, and we'll find a space to work. I have handouts. You can get notes from someone in the class for what you have missed. We may need a few catch-up sessions. You've missed quite a bit.

Anonymous said...

for the science exam will we have to know how to draw velocity time graphs and position time graphs?? or will we have the choice to use the equations??

Ms.Bearse said...

Velocity-Time graphs are the most useful...from them you can get position, velocity, and acceleration. They were a part of the course, so you should know them.

When solving a problem, you can use the equations, but you may be asked a question about graphing too...

jehanne and katie said...

do we need to know the phosphorus cylcle? cause it is on that sheet thing

Anonymous said...

will they give you information and you will need to make a velocity time graph??

Ms.Bearse said...

you dont need to know the details of the phosphorus cycle...

you need to know the carbon cycle, the nitrogen cycle, and the water should get the picture that all atoms are recycled over and over and over again.

I'm glad you girls are working hard and studying :) Send more questions when you get stuck.

Ms.Bearse said...

Making a velocity time graph from velocity data is not hard. That's a math problem from grade 9. :)

I'd focus more on understanding and interpreting a graph....if there is a graph shown, can you explain what is going on in the graph?

Know what the slope of the graph represents
slope of a d-t graph gives v
slope of a v-t graph gives a

know what the area under the graph represents
area under v-t graph gives d

Anonymous said...

how do you know the number of electrons??

Ms.Bearse said...

Check the periodic table. The atomic number tells you the number of protons (and the number of electrons for an atom). The number of electrons change when the atom becomes an ion. the atom will lose or gain electrons to get a full valence shell (outer shell)

Dan said...

You must have thought you'd heard the last from me. I had a few things that I wanted to check on for tomorrow. First of all I heard that we wouldn't be givin the physics equations for the exam, is this true? Secondly I'm not too sure about the conduction/convection/radiation idea, could you give me a quick definition? And last of all, what about the clouds? It says on the review sheet cumulus, an stratus, is that all we need to know? Thanks alot. ,Dan

Ms.Bearse said...

Hi Dan,
You DO get the physics equations/ions/periodic table stuff.

Radiation is how energy gets to Earth from the sun (electromagnetic waves, light, etc). Conduction is when something warm touches something cold, and the heat gets transfered. Convection is when hot air (or any fluid really) rises, and cools and then falls. You see that in the atmosphere and in the oceans (and in a pot of boiling water too).

You need to know how clouds form, different types of clouds, etc. We saw lots of it in the movies, and people talked about it in their presentations.

Good luck with the studying. See you tomorrow

Cassie said...

Ms. Bearse,
This is coming all the way from FSS.Anyway i have a question about physics. I don't really understand Vectors.I understand how to draw them but calculating the resultant displacement(WHich I don't know the definition too) and such.If you could help me with that that would be great!!

Ms.Bearse said...

Hi Cassie
check out this site (it's the notes from when I taught the course at FSS)

Vectors are arrows (it's like a length with direction). Each vector is an arrow. If you connect arrows together one following the other, then you can draw a final arrow from your starting place to the ending place. The final arrow is the resultant displacement.

Imagine that Cassie starts at school and walks 3 blocks south, then 4 blocks north. In the end, Cassie is 1 block north of the school. That is her resultant displacement.

You can have displacement in other directions too, in which case, you draw them carefully with a protractor, and ruler, and then you can state the final displacement (always with the starting point as your reference--state the length and direction you'd need to travel to get to your ending point)

The difference between distance and displacement is key in this course. Imagine the walking example I gave you above. The displacement is 1 block north. The distance however is 7 blocks. You actually walked 7 blocks (no direction stated because distance is a scalar--opposite of a vector).

I'm not sure if that helps you, but I'm sure that my notes might clarify a bit. The text book should have some good pictures too. Most high school students dont appreciate how much learning can happen from reading the text book! Give it a try, talk to some of your choir buddies--I'm sure one in particular can be a good help. :)

Have a good night.

Ms. Bearse

Anonymous said...

sry i posted the question in the wrong forum :( silly me. . anyways i have another question :). . . what is a hazard of pesticides?

Ms.Bearse said...

Pesticides are a hazard if they can be stored in the fat tissue of an organism. They can't escape from the body of the organism, and over their life, the pesticides can build up to pretty high levels.

When that organism is eaten by another one, all of the pesticides go along with it.

At the top of the food chain, the organism will end up with a collection of all the pesticides that its food, and its food's food have eaten over their lifetime.

This can be very bad for the animal at the top of the food chain. They can get really sick and die.

Anonymous said...

ms. bearse... drawing a blank on combustions, you need:
hydrocarbon + ? = carbon dioxide + ? thanks for the help

Ms.Bearse said...

hydrocarbon + oxygen gas--> water + carbon dioxide

if it is incomplete combustion (due to lack of oxygen), the reactants are the same, but the products would be water + carbon dioxide + carbon monoxide + carbon.

Hope that helps. I'm in rm. 204 tomorrow all day (except lunch) to help with questions.