Molecule Shapes Simulation Answers

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Are you looking for Phet Interactive Simulations Molecule Shapes Simulation answers? If so, you are able to check the answers below according to the StuDocu site that you are able to access at link here. It is important for you to note that you are able to use the answers below for learning, but make sure that you do not use it for cheating.

Part I: Electron Domains

  1. Explore the Model screen of the simulation. As you explore, answer the following questions.

a. How does adding an atom affect the position of existing atoms or lone pairs?

Answer: As the atoms get closer together, the bond angle keeps decreasing.

b. How does adding a lone pair affect the position of existing atoms and lone pairs?

Answer: Same as adding an atom.

  1. Is the effect of adding bonded atoms and lone pairs to the central atom similar?  Explain why this could be the case.

Answer: Correct. Both types of domain take up the space. They repeal other electron domain.

We can think of a bond or a lone pair of electrons as a “domain” of electrons. Single bonds, double bonds, and triple bonds each count as one domain.
  1. How do the electrons in bonds (bonding domains) differ from lone pairs (non-bonding domains)?

Answer: Electrons in bonds are shared between 2 atoms. Electrons in lone pairs only belong to 1 atom.

  1. What happens to the bond angle when you add or remove an electron domain?

Answer: The bond angle decreases.

  1. Can you force the atoms into new configurations by pushing atoms around?  What does this suggest about the configuration of atoms in real molecules?

Answer: Yes, you can, but it won’t stay in a different configuration, it will adopt the lowest energy geometry.  The configuration of atoms in real molecules is flexible.

  1. What is the difference between Electron Geometry and Molecule Geometry?

Answer: Electron Geometry accounts to all domains; Molecule Geometry only accounts for bonding domains.

  1. In one or two grammatically correct sentences, write a definition for the term Molecule Geometry.

Answer: Molecular geometry is a term in chemistry used to describe the shape of the molecule. It is the arrangements of atoms in relation to a central atom in a three-dimensional space.

Part 2: Drawing Molecules to Show 3-Dimensionality

  1. Where is each of the 5 atoms in the molecule CHFClBr?

In the plane of the paper _____ _____ _____

In front of the plane of the paper _____

Behind the plane of the paper _____

  1. Using the Model screen, add bonding domains (●) to the central atom ( ). Using lines, wedges ○and dashes from Model 2, draw each molecule’s shape.
Bonding Domains Around Central Atom Drawing of Shape Electron Geometry Bon Angles
2 ● ─ ○ ─ ● Linear 180°
3 Trigonal planar 120°
4 Tetrahedral 109.5°
  1. In the Model screen, build a molecule with 5 atoms attached to the central atom. Look at the molecule geometry and electron geometry. Predict what will happen to the molecule geometry as you replace atoms with lone pairs.

Your Prediction: Five atoms would give us EG and MG of Trigonal Bipyramidal.

  1. In the following table draw the molecule geometry. As a group, make a prediction for each first, and then compare your answers with the simulation.

Predict First, Then Compare with the Simulation

Number of Domains Around Central Atom 1 Lone Pair 2 Lone Pairs 3 Lone Pairs 4 Lone Pairs

Part 3: Comparing Model Vs. Real Molecules

  1. Explore the Real Molecules screen.

a. List the molecules that show a difference in bond angle between “Real” and “Model”. Note: differences in bond angle may be small.

Molecule Number of Lone Pair Domains
H2O 2
CIF3 2
SO2 1
NH3 1
SF4 1
BrF5 1

b. What do all of the molecules in the table have in common?

Answer: All of them have at least one lone pair

c. What trend do you observe that distinguishes lone pairs from bonding domains?

Answer: More space is taken

That’s all the answers from and then for the next numbers, the answers are from as you are able to check below.

  1. Use the simulation to build a system with 5 domains.  This is called a trigonal bipyramidal structure.  The two different sites in a trigonal bipyramid are labeled as A and B in the drawing to the right.

f. Each A atom is adjacent to 3 B atoms. What is the A-B-C bond angle?

Answer: A-C-C= 90

g. Each B atom is adjacent to 2 A atoms and 2 B atoms. What is the B-C-B bond angle.

Answer: B-C-B=120

h. In a system with 4 atoms and 1 lone pair, predict whether the lone pair will be in a B site or an A site? Explain.

Answer:  it will be the B site because a more electronegative center tends to be on the equatorial plane.

i. Examine the molecule SF4 in the Real Molecules screen to check your prediction from question c.  Which interactions are more important in determining where the lone pair will go?

Answer: Electronegativity

That’s all the answers that I can give to you according to the StuDocu. If you need more of this section, you are able to access the site that has been mentioned above.

About PhET

PhET Interactive Simulations is an open educational resource project that creates and hosts explanations which can be explored and it is non-profit. Nobel Laureate Carl Wieman founded it in 2002. PhET stands for Physics Education Technology.

As explained on the PhET site, this educational resource project provides fun, free, interactive, research-based science and mathematics simulations. The team of PhET extensively test and evaluate each simulation to ensure educational effectiveness where the tests include student interviews and observation of simulation use in classrooms.

Now, the project designs, develops and releases over 125 free interactive simulations for educational use in the fields of physics, earth science, biology, chemistry, and mathematics. As explained on Wikipedia, the simulations have been translated into over 65 different languages and some of them are Chinese, Spanish, German and Arabic.

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