Science 10/7/10

Bell Question:  Draw an atom of Nitrogen.

Proton:
-positively charged
-exist in the nucleus
-have a mass of 1 Atomic Mass Unit (AMU)
- determined by the Atomic number

Electron:
-negatively charged
-exist in energy shells
-has a mass of 1/1836th of an atom
- strength of a proton

Neutron:
-neutrally charged
-has mass of 1 AMU
-exists in the nucleus

Octet Rule:
Rule of 8
1-2 electrons
2- 8 electrons
3- 8 electrons
not in 4-7 shells

Science 10/1/10

Bell Question:  Look at your notes and write down what you aren't sure of.
-  *cricket chirps*
Jk
The Definitions of:
-Element
-Compound
-Solution
-Mixture

HISTORY  LESSON

1880 -Thomson- Plum Pudding model of the atom

1920s- Rutherford- given credit for the positive nucleus- Nobel prize for his discovery.

 

1940s- Henry Chedwick- given credit for the neutron

1945- Niels Bohr- astronomer

 What we use today:

Bell Question Continued:

Element-an atom that cannot be broken down anymore than it is.

Mixture- a heterogeneous combination of compounds and molecules and elements.

Science 9/29/10

Bell Question:  How do all the ingredients in Sprite mix together?

-All the ingredients in Sprite mix together because of the spacing in between the molecules.

Signs of a Chemical Reaction:

-exothermic heat reaction

- color change

-gas given off

- new product or item

Precipitate- The solid formed as a result of a chemical reaction

Plasma- Charged gases

HISTORY   LESSON

1600s- The atom developed by the Greeks

Atomos- smallest indivisible particle

1800s- Dalton- views of the atom

Dalton's Views:

1. Atoms are the smallest thing out there

2. Atoms make elements

3. Atoms of similar elements are similar

4. Atoms of different elements are different

1900s- Thomson- Given credit for the electron

Science 9/27/10

Bell Question: Is cooking a piece of chicken on the BBQ a chemical of physical change? Why of why not?

- It would be a chemical change because it is creating a new product by smell, color, exothermic reaction, etc.

Molecule- the simplest part of a compound that is still a compound.

Density does NOT equal weight!

-Everything has an equilibrium density. They all want to be at their own equilibrium density.

Solution- a homogeneous combination of matter

Solute- what you put in the material. Generally the solid.

Solvent- the liquid you put in the material (water is universal solvent)

Unsaturated- not enough solute to fill in the spaces of the sovent

Saturated- just enough to fill in all the spaces in the solvent (under normal conditions)

Supersaturated- more solute that the solvent can handle (under normal conditions)

Science 9/22/10

Bell Question:  Compare and contrast a chemical and a physical change.

-A chemical change is the changing of the chemical make-up of an object

-A physical change only changes the appearance of an object

--- They both change something in the object.

Definite Chemical Reaction:

- color change

- gas given off

-energy change

Exothermic- heat leaves system 

Endothermic- heat enters system

Science 9/20/10

Bell Question: What and how much is in each compound?

1.  H2SO4           Hydrogen 2

                           Sulfur 1

                           Oxygen 4 

2.  Na Cl            Sodium

                          Chlorine

3.  K Br             Potassium

                          Bromine

4.  Ca CO3       Calcium

                          Carbon

                         Oxygen 3

If you had a block of wood and the density was 1.12, what would I have to do to change the density? 

-You would have to change to block of wood's mass to change the density.

Physical Change- change the appearence

Chemical Change- change the chemical make up

Science 9/14/10

Bell Question:  Name each symbol:  Are elements homogeneous or heterogeneous?

   N-  Nitrogen

   Br- Bromine

   Na-Sodium

   K-  Potassium

   Cu- Copper

- Elements are Homogeneous because they involve compound and compounds are homogeneous.

Compound: combination of elements

                   CO2   NH3

Atomic Number =

Number of Protons   =         All the Same Number

Number of Electrons=

Protons + neutrons= Atomic Mass

Physical Properties- properties that describe the matter

* color, mass, inertia, volume, density, temperature, texture, weight, shape, etc.

Chemical Properties- the way a chemical change occurs

* rusting, burning, chemical reaction, ionization energy, electronegative, etc.

Density =    mass

                    volume

Science 9/10/10

Bell Question:  What is not matter?

-Fire,thoughts, light, etc. are  not matter.  Fire is energy and thoughts are not matter either because thought sand light do not have mass and volume.

Matter: anything that takes up space and has mass.

Science 9/8/10

Bell Question: How many millimeters are in 10 meters?10,000   How many kilograms are in 40 grams?0.04  What is the difference between a theory and a law?

Theory:  has NOT been proven as a true FACT

Law:  has been proven as a real and true FACT

Science 9/3/10

Bell Question:  What is the base units in the metric system for; length, mass, volume, time?

Length- Meters

Mass- Kilograms

Volume- Liters

Time- Seconds

SI- System International

Science 9/1/10

Bell Question: Determine the number of significant figures:

1.  .00249            3

2.  860900.0        7

3.  8675309         7

Scientific Notation- used to write very large or very small numbers

Large Numbers in Scientific Notation:

1.  Write down all significant figures

2.  Place a decimal point between the first and second number

3.  Raise the number to the tenth power to the number of places you count from the right

                 9476400000        -        9.4764x10e9

                 6.72349x10e10    -        67249000000

Small Numbers in Scientific Notation:

1.  Write down all significant figures

2.  Place a decimal point between the first and second number

3.  Raise the number to the left

4.  Raise the tenth's power to the negative exponent representing large numbers in scientific notation

                  .00000864         -          8.64x10e-6

                   6.983x10e7      -           .000006983

Science 8/30/10

Bell Question:  Describe where you have used the 3 types of graphs?

-I've used graphs in Math, Science, and at home using Microsoft Office Exel.

Random Questions:  Is it accurate?  Was it Measured?  Does that number have meaning?

Significant- has meaning (digits or figures)

What is Significant?

1.  All nonzero numbers

          123.478-significant figures

2.  Zeros between significant figures

          207- significant

3.  Leading zeros are NOT significant

          .0003723-not significant

4.  Trailing zeros in a number with a decimal point

          1.00000- significant

How many significant numbers?

A) 573            - 3 significant

B) 502.00       -  5 significant

C) 87              -  2 significant

D) .000283     - 3 significant

 Rules for Significant Figures:

1.  Multiply and Divide

     - your answer can only be significant to the least signigicant amount of significant in you problem.

             23.2 x 87.97 x 56.9287 - can only have 3 significant figures

2.  Adding and Subtracting

     - your answer can only be stated in decimal places that you have in your problem.

            23.2 + 48.76 + 89.789  - can have significant figures somehow

-a student who needs help

Science 8/26/10

Bell Question: What is a graph? What are some types of graphs?

-A graph is a visual that shows you data. Bar graph, Line Graph, and Pie Chart. A graph is a picture of your data.

Line Graph- Shows trends

Bar Graph- Shows comparisons

Pie Chart- Shows comparisons to a whole

Important Points for a Line and Bar Graph:

-scale

-Placement of information on the axises

Independent variables- don't change, on y axis

Dependent variables- changeable, on x axis

-Label the graph/ use legends

How to Develop a Pie Chart:

1. Determine the number of parts that make up the chart

2. Develop percentages

3. Plot the percentages

4. Label the parts

5. Label the chart

- a student who needs help

Science 8/24/10

Bell Question: What is the scientific method and why do we need one?

1. Observation 2. Question 3. Hypothesis 4. Test 5. Data 6. Conclusion

-We need it to become more accurate in our thinkings. Used to figure out unknowns.

Hypothesis-A possible outcome

Theory- A tested hypothesis

Law- A proven fact

Possible Conclusions- 1. Hypothesis is correct 2. Hypothesis is incorrect 3. There is not enough information to answer your hypothesis

Experimental Design: When performing an experiment, remember a control- what you base your test on.