Build An Atom Simulation – Build an Ion Worksheet

Chemistry I                                                                                 Name: Brandon Jansen

                                                                                                            Date: Feb. 5, 2013

“Build An Atom” Simulation – Build an Ion

Learning Goals:

1.     Draw models that show atomic structure.

2.     Use information about the number of protons, neutrons, and electrons to identify an element, its position on the periodic table.

3.     Predict how changing the number protons and electrons will change the element and its charge.

Accessing Prior Knowledge:

1.     What 2 sub-atomic particles have charges? List the particle name and its charge.

Protons, which have a positive charge and electrons, which have a negative charge.

2.     What does the term “neutral” mean?

       It means that protons and elections cancel out.

3.     Describe which particles and how many of each you need to make a neutral beryllium atom. (Round the atomic mass from the periodic table to the nearest whole number to get part of your answer.)

Would need an atomic mass of 9 and a atomic number of 4. If you want it to be neutral you need to have the same protons and electrons so you need to have an ion charge of 0.

Directions:

§  Go to the following website:  <http://phet.colorado.edu/en/simulation/build-an-atom>

§  Click the green “Run Now” button below the large image to start the application.

§  Play around with the simulation for a bit to become familiarize with the controls and functions. You can add particles to your atom by dragging them into the atom model. The “Element”, “Mass” and “Net Charge” boxes should be expanded.

§  Note that when particles are added to your model you can see if the atom is stable or unstable (labeled in the center), and if it is neutral or an ion (labeled on the outer rings). An ion means there is an overall charge to the atom.

§  When you are ready to start the exercise, press the “Reset All” button in the bottom left corner to clear any changes.

Part I: Basic Electron Structure

1.     Where are the electrons located inside of the atom?        

Make sure that the simulation is set to the “orbital” model. The model shows two orbits, which we often call energy levels. The first energy level is the one closest to the nucleus, and the second is furthest away.

2.     How many electrons can fit in the first energy level?

Only 2 can fit in the first energy level.

3.     Can you ever have more than this number in the first energy level? Can you ever have less?

No you can never have more than two and you can have zero or no electrons in the first energy level.

4.     How many electrons can fit in the second energy level?

      8 electrons can fit in the second energy level.

5.     Build some atoms, and write down three examples that have a stable nucleus and neutral charge. This time, do not draw individual protons and neutrons, just draw one small dot for the nucleus.

White	Black
Electron	Nucleus

Include a drawing of your atom. The key above is a suggestion for how to draw the parts of your atom.

Be sure to draw the electrons in the correct energy levels.

	Picture of Atom
Electrons: 2 Protons: 2 Charge: 0		Name: Helium Symbol: He
Electrons: 7 Protons: 7 Charge: 0		Name: Nitrogen Symbol: N
Electrons: 10 Protons: 10 Charge: 0		Name: Neon Symbol: Ne

Analysis Questions:

1.     The atomic number on the Periodic Table will tell you how many protons are in the nucleus of each atom. From your observations, how can you predict the number of electrons in a neutral atom? Explain you answer.

Since the charge is 0 and the atom is neutral the number of electrons has to be the same as the number    of protons in the atom.

2.     Without using the simulation, draw 2 atoms you have not yet made in the simulation. Pay attention to the electrons, and only pick an element in the first two rows of the periodic table.

Atom “A”

Atom “B”

 

Part II: Making Ions

Not all atoms are neutral. Many have a charge. Some are more positive and some are more negative. We call the charge on such an atom the “net charge”, or “total charge”.

1.     Make a neutral Beryllium atom. What would you do to make a beryllium atom with a negative charge?

      You would have to have more electrons than protons by one.

2.     Make the neutral Beryllium atom again. What would you do to make a beryllium atom with a positive charge?

      You would have to have more protons than electrons by one.

3.     Expand the box labeled “Net Charge”. Pick an element, and make two example of the same element with different charges in the table below. Include what the charge is (sign and number), and how many protons and electrons are in the atom.

Name of element: Sulfur         Symbol: S

Charge: -2 Electrons: 18 Protons: 16

Example 1

Charge: +2 Electrons: 14 Protons: 16

Example 2

4.     What did you do to change “Example 1” to “Example 2”?

       I just switch the ion charge so the atom has a positive and a negative charge.

5.     Repeat the last process for a different element. Make two examples with different charges.

Name of element: Barium       Symbol: Ba

Charge: +2 Electrons: 54 Protons: 56

Example 1

Charge: -2 Electrons: 58 Protons: 56

Example 2

6.     Based on your observations, make a rule or formula to predict the charge of the atom if you are given the number of protons and electrons.

To find the charge you subtract the number of protons by electrons and you will find the charge say 4-7=-3, the charge will be -3.

7.     Now you will practice building some specific elements. In the table below, some of the information is filled out about a particular atom. Complete the table below by filling in the blanks and drawing the picture of that atom.

	Picture of Atom
Electrons: 10 Protons: 8 Charge: -2		Name: Oxygen Symbol: O
Electrons: 2 Protons: 3 Charge: +1		Name: Lithium Symbol: Li
Electrons: 10 Protons: 9 Charge: – 1		Name: Fluorine Symbol: F
Electrons: 0 Protons: 1 Charge: +1		Name: Hydrogen Symbol: H
Electrons: 2 Protons: 5 Charge: +3		Name: Boron Symbol: B