You came back!!! Welcome to Week 2 of the 2020-21 school year. You are in for a treat this week as we learn about elements and how they are arranged on the periodic table.
[Insert Week 2 Intro Video]
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Week 2 Lesson: The Periodic Table
Week 2 Pre-Assessment
Part 1 – Chemical names and symbols
Part 2 – Properties of the elements
Part 3 – The periodic table
Part 4 – Models of the atom
Part 5 – Atomic number and atomic mass
Week 2 Quiz
Checklist of required week 2 work:
Week 2 pre-assessment
Part 1 assignment
Part 2 assignment
Part 3 assignment
Part 4 assignment
Part 5 assignment
Week 2 quiz
Congratulations! You have completed the learning for Week 2. Check back on Monday, September 21 for the next weekly lesson.
Early chemists were known as alchemists. Notice that both chemistry and alchemist include “chem” in the word – the Wikipedia entry for the article Etymology of chemistry is an interesting read and helps explain the ancient global origin of the words. The foundations of modern chemistry actually owe a lot to ancient scientists known as alchemists. For nearly two thousand years, people in Africa, Asia, and Europe were actively engaged in alchemy: the work of turning ordinary (readily available) matter into gold and other substances perceived to be valuable. For more on the history of alchemy, watch the Crash Course video below:
Why has gold become such a desired metal? Civilizations throughout history have used gold as a display of wealth and power. The desire to possess gold, especially the gold of other nations, has resulted in countless wars throughout history. Through this lens, it makes sense that alchemists sought ways to create gold from other materials. More gold should equal more wealth, and perhaps if there was enough gold, nations would stop trying to take gold away from each other by force. By that logic, do you think alchemists were successful?
Penny Lab
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Previously, we reviewed the concept of volume as a measure of how much space a substance occupies. For example, imagine you have an object in the shape of a cube. From geometry, you remember that to calculate the volume of a cube, you simply need to measure the length of one side and then cube that value:
Vcube = side x side x side = side3
A cube with a side of length 2.8 cm would have a volume of:
Vcube = 2.8 cm x 2.8 cm x 2.8 cm = 21.95 cm3
If the cube has a mass of 59.27 g, we can use the mass and volume to calculate the density of the cube using the formula density = mass / volume (D=m/v). Inserting what we know into the equation: D = 59.27 g / 21.95 cm3 =2.7 g/cm3
We know that density is an intensive property. It can help us identify what the block is made of (assuming the block is a pure substance).
In the example above, we were tasked with calculating the volume of a cube. There are a number of familiar geometric forms, like rectangular prisms and spheres, that have formulas for volume that should be familiar to you (click here to review).
Question 10: A student fills an empty balloon with helium gas. Conveniently, the helium-filled balloon is a perfect sphere! The student measures the radius of the balloon as 10.3 cm. Calculate the volume of the balloon.
A graduated cylinder is used to most accurately measure the volume of a liquid. A graduated cylinder is also a really useful tool for measuring the volume of an irregularly shaped solid. We call that technique “water displacement” and the video below will explain how to do it:
Important things to note:
Volume is unaffected by mass. Two objects can have the same volume but different masses.
The relationship between mass and volume is density. Remember, density is equal to mass divided by volume.
Volume can be measured in base units of liters or meters. In our example of the cube, volume was measured in cubic centimeters (cm3). In the water displacement method video, volume was measured in milliliters (mL).
When reading a graduated cylinder, bring your eye down to the level of the meniscus. The liquid in a graduated cylinder will form a U-shape. Read at the bottom of the U. Click here for more on how to read a graduated cylinder.
Question 12: A student wants to know if her gold-colored chain is solid gold or gold-plated (another metal covered in gold). After consulting the list of the densities of common materials, she knows the expected density of gold. Next, she measures the mass of her chain using an electronic balance and finds it to be 2.4 grams. What is the expected volume of the chain if it is really solid gold?
Question 13: What technique should the student use to determine the volume of her chain?
Question 14: Why does the overall size of a graduated cylinder affect how accurately we can measure volume?
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Our study of chemistry begins with the question: What is chemistry? Simply stated, chemistry is the study of matter and how it can be changed. In previous years, you learned that matter is anything that has mass and volume (takes up space). Students often ask, “what is the difference between mass and weight?” Mass is directly related to the number of atoms in a substance. For example, you are made of atoms. Your mass is the same whether you are on Earth or Mars. However, weight is dependent on gravity. Earth is more massive than Mars, so the force of gravity is greater. According to an article on Space.com, the gravity of Mars is 38% that of Earth. To figure out your weight on Mars, multiply your weight in pounds by 0.38 and that’s how much you would weigh. For example, if you weigh 100 pounds on Earth, you would only weigh 38 pounds (100 pounds x 0.38) on Mars!
In chemistry, we will often use mass in our analysis of matter. Certainly the chemistry of matter on Earth is very important, but so is the chemistry of matter on Mars, the Sun, and everywhere else in the Universe. As students of science, we want our learning to apply as widely as possible! Mass is measured in base units of grams (g). The amount of space something takes up, called volume, is measured in base units of liters (L). Distance is measured in base units of meters (m).
The meter is one of 7 fundamental units, called SI Units (read more about them here). The SI unit for mass is the kilogram (kg). The prefix kilo- means 1000, so adding kilo- to the base unit of gram means 1000 grams. Similarly, one kilometer (km) is equal to 1000 meters, and one kiloliter (kL) is equal to 1000 liters. Other commonly seen prefixes include milli- (1/1000) and centi- (1/100). For example, there are 1000 millimeters (mm) in 1 meter, and 100 centimeters (cm) in 1 meter.
Question 1: How many mm are in 1 cm?
Brain break! Check out this inspired piece of musical art by the famed middle school science and math teacher Pete Hendley (aka KILA META):
…and we’re back. Meters, liters, and grams are all considered extensive properties of matter. An extensive property is specific to the amount of matter and therefore changes if the quantity of a substance changes. Imagine you have an empty two-liter (2 L) soda bottle. You measure out 500 mL of distilled water in a beaker and pour it carefully into the bottle, using a funnel to be sure not to spill.
Question 2: How many liters is 500 mL?
Question 3: After adding the 500 mL of water, what fraction of the 2 L bottle is filled with water?
Next, you measure another 250 mL of water in your beaker and carefully pour it into the bottle, increasing the volume of the water to 750 mL. This demonstrates that when we change the amount of liquid in the bottle (the volume of liquid), the number representing the volume also changes. Therefore, volume is an extensive property. Great job! Mentally pour out the water and then continue reading.
Earlier, we discussed the difference between mass and weight. If you have a bathroom scale at home, you can measure your weight in pounds. In science, we measure mass using a balance. Many students first learn to measure mass using a triple-beam balance. In high school chemistry, we work with small amounts of mass and often choose to use an electronic balance which allows us to precisely measure down to the nearest tenth or hundredth of a gram. On Earth, you can approximate your mass by taking dividing your weight in pounds by 2.2. For example, a person weighing 154 pounds would have a mass of about 70 kilograms. Similarly, you can calculate your approximate weight on Earth by multiplying your mass by 2.2.
Question 4: Calculate the approximate weight (in pounds) of aGerman Shepherddog with a mass of 35 kg living on Earth.
Question 5: Imagine the 35 kg dog from Question 4 takes a rocket to Mars. Calculate the approximate weight of the dog on Mars.
Question 6: For the German Shepherd from questions 4 and 5, what is the mass of the dog on Mars?
Back to our experiment! Imagine you measure out 500 g of liquid water using your electronic balance. As before, you carefully add the water to the empty 2 L bottle using a funnel. Next, you measure out an additional 250 g of water using the electronic balance and add that to the bottle.
Question 7: What is the final mass of water in the 2 L bottle?
Question 8: Is mass an intensive or extensive property?
While some properties of matter change based on the amount of matter present (extrinsic properties), others do not. Intensive properties do not depend on the amount of matter present and therefore can be used to identify matter. Intensive properties include density, boiling point, and the color of an object. Liquid water has a density of 1 g/mL (1 gram of water occupies a volume of 1 milliliter). Liquid water boils at 100 degrees Celsius (212 degree Fahrenheit). Liquid water is colorless (clear). If you were given the 2 L bottle from the thought experiment above, but did not know the identity of the liquid inside, you could quickly determine the color and then measure the density and the boiling point. That information taken together would help narrow down the identity of the liquid to likely be water. However, if you measured the mass or volume of the unknown liquid, that data would not help you determine the identity of the liquid, as you can imagine an infinite number of substances with a mass of 750 g or a volume of 750 mL.
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As you work through this week’s lesson, you will have opportunities to engage as deeply in the material as you find helpful. There are videos, links to articles, vocabulary terms used in context, and plenty to read to expand your understanding of the world around you through the lens of chemistry.
Weekly lessons are broken up into sections, called parts. Each part will roughly correspond to one day of work. Some parts may be longer than others depending on the learning demands of the content. Pace yourself accordingly. You are welcome to complete one part each day, or do more or less depending on your needs that day. As long as you complete the work before the next week’s learning becomes available (weekly posts become visible at 8:00 am each Monday morning), you will stay caught up!
As you work through each part of the weekly lesson, you will see questions in red text. At the end of each part, you will find a link to a Google Form assignment (log in with your student Gmail account). Assignments are auto-scored, and you may re-take assignments to earn an improved score after reviewing the learning needed to do so. Completion of the assignment will help determine your grade in the class, as will the weekly quiz. The quiz may be taken once, so do your best work. Note: If you feel your quiz score does not accurately reflect your commitment to learning the weekly work, and if all of your assignments are complete for the week, email me and I will provide access to an alternate version of the quiz.
Before you complete the assignments and take the weekly quiz, understand the resources you have available for help guide you in your learning:
At the end of each part of the lesson, you will find a link to a Jamboard – basically a place to post digital sticky notes that will serve as a discussion board. You are encouraged to post questions, post answers, and use the space to share ideas, support each other, and make friends.
You will have “class time” each day to meet with your classmates and teacher in Zoom breakout rooms to discuss the learning.
Form a study with your classmates and find a system for meeting and sharing ideas and questions that works for the group.
And you can always email Mr. Swart with questions or for help setting up peer study groups.
We begin the year with a short week, so let’s dive in! Click here to return to Week 1 – The Golden Penny and get started by taking the Week 1 Pre-Assessment.
Welcome to our first week of the 2020-2021 school year. The fact that you have chosen to visit this page is truly exciting! While distance learning has inevitably changed the way we are doing school this year, my goal is to provide you with the opportunity to engage with chemistry at a level that will prepare you for advanced science coursework both in high school and beyond.
[Insert Week 1 Intro Video]
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Welcome to Week 39! You made it! This will be a year we will all remember. It has been my great pleasure getting to know you this school year and teaching you about science. You are welcome to turn in any work from 4th quarter (Unit 4, beginning with Week 30) until noon on Friday, June 19. If you revise an assignment and would like it re-graded, please also re-share the link.
Before you head off into your bright future, please complete the Week 39 Attendance Check-In. Finally, please consider watching the videos below and use what you learn to re-make our community, our country, and our world for the better.
Some of our deepest scientific insights have come from the most basic of questions. For our last lesson of the week, we will dig into the question: What is light?
The short answer to the first question (what is light?) is that light is what we experience as a narrow band of waves of specific wavelengths within the visible part of the electromagnetic spectrum. A particle of light is called a photon. Visible photons (light) have properties of both a particle and a wave. Photons travel in waves, and waves can be described mathematically by measuring wavelength, amplitude, period, frequency, and speed.
To visualize the parts of a wave, let’s bring in Bill Nye the Science Guy:
Thank’s Bill Nye! Here’s what we learned:
In the vacuum of space, nothing moves faster than light. In fact, we can say the speed of light is the cosmic speed limit. In a vacuum (like space), light travels at 300 million meters per second (3.0 x 108 m/s). Because this number does not change, it is a constant and is assigned the letter c (c = speed of light). Side note: Thanks to Albert Einstein, you’ve probably heard of the equation E = mc2. In words, the equation says that energy (E) is equal to mass (m) times the speed of light (c) squared. You already knew that c = speed of light!
To complete our study of the properties of light, we need to introduce Planck’s constant (h):
Next, let’s revisit the parts of a wave and make some connections:
The notes above introduce Planck’s constant, h, which has units of Joule • seconds. Planck’s constant (h) relates a photon’s energy (E) and frequency (f). Frequency is defined as the number of complete waves that pass through a point in one second. The faster a light wave is traveling (greatest speed, measured in meters per second, m/s), the higher the frequency (f, waves/second). Therefore, the faster a light wave is traveling, the higher the energy (E) of the wave. Energy has units of Joule • meters. Waves with the shortest wavelengths (λ) have the highest frequency (f) and therefore have the greatest energy (E).
If you followed all that (and I have no doubt you did!) you are ready for an introduction to Quantum Mechanics. Ars Technica has a fantastic 7-part series of articles focusing on Exploring the Quantum World. The Crash Course videos below are well worth the watch as well. Enjoy!
We’ve reached the end our our learning this school year. Appropriate, perhaps, that we end where we began: in the stars. Way back in Unit 1, you learned that stars fuse lighter elements like hydrogen and helium to form heavier elements up through iron. Elements with more protons than iron are created when stars go supernova. Plants and animals (yep – humans are animals) are made of star stuff – we are quite literally the product of exploding stars.
We also conducted flame tests, showing that metal cations are responsible for producing specific colors of flame when ionic compounds are burned. Now we understand that our perception of color is a result of photoreceptors in our eyes being capable of detecting specific wavelengths of electromagnetic radiation. When those receptors are activated, they send information to our brain which then decodes the signal into our perception of light and color.
When we look up at the stars, we are looking back in time, as it takes time for light to travel from its source to our eyes here on Earth. The more distant the object, the further back in time we see. It’s not too hard to imagine there might be organisms billions of light-years away that witnessed the supernova (singular) or supernovae (plural) that launched the atoms within you and me toward our remote location within the Milky Way galaxy. The force of gravity eventually caused those atoms to coalesce to form our Sun and the planets that orbit it, including the Earth. After 4.5 billion years, here we are, studying the stars:
Anyone who would like to invest further in their understanding of the stars should email me for a copy of the handout that goes along with the Star Spectra Gizmo. This activity is purely optional and available for your own personal growth. It will not be entered in the grade book.
Welcome to Week 38! For our final lesson of the 2019-20 school year, you will be exploring the connection between light and color. Whether you are taking physics or any of our other science electives next year, this lesson will be a great preview. Let’s get to it!
That’s it! No new assignments this week (spoiler alert: no new assignments next week either). Please make sure you have everything turned in by June 19. It has been my absolute pleasure teaching you chemistry this year. What a year to remember!
Remember, you can email me any time. Office hours for Science are Tuesdays from 11am-12pm and Thursdays from 1pm-2pm. Check your student Gmail for Zoom instructions.
The Art of Science 
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