What exactly is on the Periodic Table?

On a periodic table, elements that are close to each other on the table display similar characteristics.


There are 7 important periodic trends:
1. Reactivity
2. Ion charge
3. Melting Point
4. Atomic Radius 
5. Ionization Energy
6. Electro Negativity
7. Density



Reactivity
Non-metals and metals show different characteristics
The most reactive metal is Francium
The most reactive non-metal Fluorine




Ion Charge
Ion Charges of elements depend on their group (columns).
+1|+2 <-----The Variable Changes----->+3|+/-4|-3|-2|-1|0



Melting Point
The elements in the middle of the periodic table have the highest melting point.
Noble Gases have the lowest melting point.
Starting from the <- and moving to the ->, the melting point increases until it gets to the middle of the table.




Atomic Radius
The radius decreases when moving on the table, up and to the right.
Francium has the largest atomic radius.
Helium has the smallest atomic radius.



Ionization Energy
Ionization Energy is the energy needed to completely remove an electron from an atom.
Ionization Energy increases going up and the right on the table.
All the noble gases have a high ionization energy.
Francium has the lowest Ionization Energy.
Helium has the highest Ionization Energy.
It's the opposite trend from atomic radius.



Electronegativity
Electronegativity refers to how much atoms want to electrons.
It has the same trend as Ionization Energy.



Density
A measure of the quantity of some physical property (usually mass)per unit length, area, or volume (usually volume).
Energy density is a measure of the amount of energy (often inthe form of electromagnetic radiation) per unit volume in a region of space or some material.

Isotopes And Atoms

• Atomic Number - Number of Protons
• Mass minus Atomic number equals Number of Neutrons
• Isotopes - Some atomic number but different mass
• Mass Spectrometers -Are used to determine the relative abundance and mass of the isotopes of elements  

Quantum Mechanics.

On friday, we learned about Quantum Mechanics!

The Quantum theory is that electrons are like a cloud of negative energy or a wave.
Orbitals are areas in 3d space where electrons are most likely there.
The energy of the electron is in its vibrational modes like notes on a guitar or a slinky!
Photons are produced when high energy modes change to lower energy modes.

S orbitals
each orbital holds 2 electrons.

P orbitals
There are 3 suborbitals
each contrain 2 electrons
total electrons is 6

D orbitals
there are 5 suborbitals
each contain 2 electrons
total electrons is 10

F orbitals
there are 7 suborbitals
each contain 2 electrons
total electrons is 14

Bohr's Diagram

The Bohr Model
Atoms are electrically neutral

There are 2 different models that can be used to represent the electron configuration of an atom:

1st: Energy Level Model

Example: 10      0                    
               Ne                                                                                  
               Neon                                                                            
               20          This would be represented like this:                                                                      
                                                                                                                 8e   
                                                                                                                 2e   
                                                                                                               20Ne     20= atomic mass
                                                                                                               10          10= # of protons

2nd: Bohr Model

Example: 10      0      
               Ne
               Neon
               20             This would be represented like this:
                                                                                              

Electrons occupy shells which are divided into orbitals
   -2e in the first shell
   -8e in the second shell
   -8e in the third shell
   -16e in the fourth shell
   - etc.

Bohr's model

On October 15th, we learned about a man named Niel's bohr and how he came to create the Bohr Model.

Niels bohr wasn't satisfied with the model Earnest Rutherford created.His model was unstable and that protons and electrons should attract each other. So Bohr created a model based on the energy emitted by different atoms and that each atom has a specific spectra of light. To explain what he was talking about, Bohr stated that electrons occupy shells or orbitals.

Bohr's theory.
Electrons exist in orbitals
When they absorb energy, they move to a higher orbital to a lower one. They also release energy as a photon of light.

Here is a link to a program that shows how electrons move from shell to shell.


http://phet.colorado.edu/en/simulation/hydrogen-atom

Just click on it, click prediction and click on bohr. Why stop there? There are many other cool examples like  
J.J thompsons plum pudding model and John Dalton's billard ball model!

-Julius Francia :)

Atomic Theory

Democritus
- In 300BC Democritus said atoms were indivisible particles. It was not a testable theory, only a conceptual theory.

Lavoisier
- Law of conservation of mass
- Law of definite proportions

Proust
-  If a compound is broken down into its constituents the procedure exist in the sam ration as the compound

Dalton
- Atoms are solid, indestructable spheres

JJ Thompson
- Rasin Bun Model
- Solid positive spheres, with negative particles embedded in them.
- First atomic theory to have positve protons and negative charges

Rutherford
- Show that atoms have a positive, with electrons outside it

Our First Lab :0

In our first lab, we conducted an experiment to see how much salt can be dissolved in various amounts of water then make a conclusion on how much salt could be dissolved in 200mL of water, using a graph. In this graph made a line of best fit and scrolled to 200mL and from there we took our estimate which was around 38.??g of salt, but our answer was not even close. The real answer was around 70.??g of salt. Though not so dangerous, in this lab we followed procedure and wore all safety gear and followed safety precautions. In this lab it is also important to ask what temperature of water to use because your results will reflect on how much salt can be dissolved in water.

                                        
The graph sort of looked like this but this is just an example:

Density & Graphing

On Thursday, September 30th we learned how to calculate the density of an object and a couple of things about graphing.

The formula for density is:

density is usually expressed in the form Kilograms/Liters, Kilograms/meters cubed or grams/centimeters cubed.

There are 5 things a graph can have

1: labeled axis
2: Appropriate scale
3: A title
4:data points

5: a line of best fit

There are 3 things you can do with a graph

1: Read the graph
2: Find the slope
3: find the area of the graph.

Julius, Mark, Timothy