# Los Angeles City College Atom

At the bottom of these instructions are three problem sets. Your goal is to 1) choose one of those problem sets and make a video of you teaching the material (** for the video just write the problem down with explanation and script**) and, 2) with the remaining two problem sets, provide written work of the solutions.

1) Submit a YouTube video of you teaching one problem set. (50%)

Imagine you are in front of the classroom teaching a class how to do the problem set for the first time. There are many approaches of how to teach effectively. Use an ipad, whiteboard, or start with a* blank page.* **Do not start with any pre-written material in the video.**

You will be graded on:

- Did you introduce the topic and provide enough
**details and background information**so that a new chemistry student can understand the steps? - Was the presentation
**clear to follow both visually and logically**and did you start the presentation without preprepared written information? - Is the problem
**accurately**explained and solved?

2) Submit a pdf of written work for the other two of the problems sets. (50%)

Present the problem set solution by answering the question while providing about **a paragraph or two of written explanation** on the thought process of how to solve the problem and of each step taken. Use bullet points, label individual steps, and write in complete sentences. Do not just provide the answer or solution. Without explanations accompanying EACH STEP, you will not receive full credit.

**Problem sets**

**Problem Set 1**

Solve the following problem showing and explaining ALL steps. **You should provide at least a few paragraphs, bullet points, and labels EXPLAINING each individual step. **

1) A bucket is filled at a rate of 9.17 cubic centimeters per second. If the bucket has a volume of 23 liters, how many minutes will it take to fill the vessel? Express the answer to the proper number of significant figures. Use the conversion factor 1 cm3 = 1 mL. **Remember, in these exam questions, no credit is given for only showing the mathematical solution.**

**Problem Set 2**

2) How many significant figures do the following two measurements have? **In addition to answering the question provide a few paragraphs explaining why, and how that solution was found.**

985.20 meters and 430 meters

3) If you were to **add** the two numbers in question 2, above, what would be the result, rounded to the proper number of significant figures? **In addition to answering the question provide a few paragraphs explaining why, and how that solution was found.**

4) If you were to **multiply** the two numbers from above, what would be the result, rounded to the proper number of significant figures? **In addition to answering the question provide a few paragraphs explaining why, and how that solution was found.**

**Problem Set 3**

Solve the following problem showing ALL steps. **In addition to showing the solution provide a few paragraphs, bullet points, and labels explaining the individual steps.**

A made-up element has three isotopes with masses and abundances as follows:

Atomic mass (amu) |
Percent Abundance |

19.00 |
35.9% |

20.00 |
20.1% |

22.00 |
44.0% |

5) Determine the average atomic mass of the element.

6) If you had 27.1 grams of the above element, how many atoms would be present?