Category: Homeschool Science

Arguably one of the greatest contributions to the field of chemistry, the periodic table of the elements is more than just a graphical arrangement of symbols and numbers. Who was responsible for this monument of scientific history? And how can we as scientists make the most of the periodic table in our studies?

What is the periodic table of the elements?

The periodic table is a structured grouping of the 118 identified elements in our world. The table is organized into rows called periods and columns called groups. The groups contain elements that have similar chemical behavior.

Each block on the periodic table is a snapshot of one element that lists its:

1. Chemical symbol
2. Atomic number
3. Average atomic mass of its isotopes.

You can investigate the periodic table to find patterns for yourself.

In a given period, the farther to the right the element is on the table, the smaller it is, the more electronegative it is, and the higher its ionization energy. By contrast, in a given group, the farther down the element is, the larger it is, the less electronegative it is, and the lower its ionization energy.

You will also find that the elements can be separated into metals, nonmetals, and metalloids. Most periodic tables use color to identify these categories, but the elements far to the left are metals, the ones to the far right are nonmetals, and some of the elements in between are metalloids.

The periodic table is a wonderful resource for solving chemistry problems and equations.

 

The names and letter symbols of the elements come from various sources such as 

1. Latin (aurum for Au – Gold or natrium for Na – Sodium) 
2. Greek (kryptos/stranger for Krypton or baris/heavy for Barium)
3. Other languages (Spanish platina/little silver for Platinum or the old Anglo-Saxon/Celtic word ludaihe for Lead and the Latin word plumbum which became lead’s symbol Pb)
4. People (Curium or Einsteinium)
5. Places (Americium or Ytterbium)
6. Planets and Asteroids (Plutonium or Cerium)

In addition to using this valuable resource for high school chemistry, younger homeschool students can familiarize themselves with the periodic table through word and number games, or hands-on discovery of elements around them.

• Find interactive tables that list actual everyday uses for all of the most common elements, and let your students find these common items around your home.
• Use the chemical symbols on the periodic table to spell words or create puzzles.
• Decorate graphic artwork or create fun science-related greeting cards with chemical symbols.
• Color the periodic table based on a properties key.
• Find books about the periodic table to bring the information to life.
• Create a card deck of the elements and make up games.
• Use sticky notes to build a periodic table on the wall as your students learn new elements.

How many more fun ways can you find for your younger students to explore the periodic table?

The History of the Periodic Table

So how did we get this graphic marvel of modern chemistry?

Dmitri Mendeleev gets credit for organizing the elements into his periodic table in 1869, Previous earlier attempts by other scientists rarely get noticed, but were excellent examples of people trying to wrangle the elements into some semblance of order.

Way back in 1789, Antoine Lavosier began listing certain substances he believed were broken down as far as they could be. He called these substances “simples”.

Then John Dalton produced a table in 1805 of atomic masses derived from mixing elements to determine what they created. Although the measurements were primitive since the ratios were unknown, Dalton did develop the atomic theory.

In 1862, Alexandre-Emile Beguyer de Chancourtois devised a 3D model he called a telluric screw. This device, when rotated, displayed the atomic weights of certain elements at regular intervals and clearly showed a “periodic” occurrence of these weights.

John Newlands also noticed patterns among the atomic weights of elements and created an arrangement in 1865. His Law of Octaves compared these patterns with musical notes arranged in scales. The reason he used intervals of 7 is because the noble gasses hadn’t been discovered yet, and didn’t leave spaces for future discoveries. But he was on the right track and eventually got credit for his discovery.

Around the same time as Mendeleev was designing his periodic patterns, Julius Lothar Meyer recognized the periodicity of elements. At first, he played with just a few elements and made a chart of how they combined with each other, then later added the transition metals. His chart was very similar to the one Mendeleev published, but Meyer’s work was published a year later, so he deferred to Dmitri as the first.

Mendeleev sorted and arranged the elements into the original precursor table of our current table. He intuitively placed elements in their places based on their atomic weights as well as their properties in relation to similar elements. Since he was fond of card games, Dmitri initially used paper cards with atomic weights and arranged elements into groups he called “suits”.

An important feature of his table were the gaps he left for undiscovered elements and he even made predictions as to the characteristics of five of them. These predictions turned out to be accurate. Then when the noble gasses were discovered in the 1890s, they fit right into the table, further proving Mendeleev’s work.

It turns out, Dmitri’s table even anticipated and provided evidence to prove atomic structure, something scientists of the time had not discovered.

Mendeleev said of his discoveries:

“Before the promulgation of this law, the chemical elements were mere fragmentary, incidental facts in Nature. The law of periodicity first enabled us to perceive undiscovered elements at a distance which was inaccessible to chemical vision.”

He also said:

“Elements arranged according to the size of their atomic weights show clear periodic properties. All comparisons which I have made…lead me to conclude that the size of the atomic weight determines the nature of the elements.”

Finally, in 1913, Henry Moseley used x-rays to measure the wavelengths emitted by certain elements and then used a frequency calculation to figure out that atomic number actually represents the number of protons in the atoms that make up the elements.

Even in 1945 scientists were still making new discoveries and expanding the usefulness of the table. Glenn Seaborg made a discovery concerning a group of elements that modified the arrangement of one portion of the table, giving us the current version.

The Periodic Table in your homeschool

As you can see, many scientists contributed to the methodical organization of the elements in our world, and the periodic table continues to evolve today. With Mendeleev’s periodic law, the table continues to provide opportunities to discover new elements, and the periodic table as we know it today is a most useful scientific tool.

You will explore the periodic table of the elements more in our courses Science in the Atomic Age and  Discovering Design With Chemistry.

When it comes to exploring God and His creation, simple observation goes a long way to enhancing our appreciation and understanding of the world around us. This is how ancient natural philosophers viewed their world millennia ago.

However, we as scientists and students exploring science must take a more methodical approach to learning how our world works.

This approach is known as the scientific method, a methodical process used during scientific investigation that follows certain steps. One way those steps can be described is:

These steps are:

1. Ask a question.
2. Begin preliminary research.
3. Establish a hypothesis.
4. Test the hypothesis with experiments.
5. Evaluate the data from the experiments.
6. Draw your conclusion.
7. Present your findings.

Let’s explore these steps in more detail:

Ask a Question

The first step in learning about the world around us is observing and asking questions about what we see.

Your question is the first step in the process to discovery. Why does something happen? How does something happen? What happens during this particular set of circumstances? Your most exciting research will begin with the words “What if…?” or “I wonder…”

Ask the question you want answered and make notes of any sub-questions or related ideas that come to mind.

Begin Preliminary Research

Next, you’ll want to do a little preliminary research. The more you know about your topic, the easier it will be to conduct a relevant experiment. 

Research previous studies, read through earlier experiments, and gather information on your topic through an online search or at the library. Remember, other scientists may have asked the same question before, but your approach will be unique to you.

Establish a Hypothesis

Your next step is all about what you think based on what you’ve researched. Ask your question, read through your notes, then make the most educated guess you can.

This is called forming a hypothesis. Your hypothesis should be testable and also include predictions of what you think the experiments will show. Make notes of testable variables so you can create experiments to compare and contrast different outcomes.

Test the Hypothesis With Experiments

Now comes the fun part. It’s time to gather your materials and perform your experiments. Use your predictions and your variables to create experiments to test your hypothesis.

You will take copious notes of all your experimentation, any changes in variables you made, as well as what happened during each step of the experiment. This way, you can repeat any experiment to see if you get the same results.

You can also make drawings or graphs to help describe your results. These will help when it comes time to present your findings. Remember the preliminary research you did in step 2? You can use your own notes to research ideas for future topics for experiments!

Evaluate the Data From the Experiments

Okay, now it’s time to evaluate your data. What did you determine during your experiments? Did the results prove or disprove your hypothesis? Or did your experiments present even more questions you want to answer?

You may want to change or add variables, amend your original hypothesis, and perform additional experiments. This extra data can help you finalize your conclusion.

Draw Your Conclusion

Once you have analyzed all the data you gathered from your experiments, you can draw your conclusion. This is what you’ve been working toward!

What does it mean to draw a conclusion? During this step, you will decide if what you thought would happen, happened. Your experiments should have answered your initial question, and repeated experiments should have had the same results.

With this information, you can make a solid conclusion based on the comparison of your hypothesis and your experimental data.

Present Your Findings

Whether you’re creating a project for a science fair, completing a homework assignment, or just experimenting to learn more about the world, the last step is to present your findings.

Produce a presentation (like a display, paper, or video) with your questions, hypothesis, and results. Present your notes and drawings to someone to evaluate. Or just tuck your findings into a science notebook filled with other wonders you’ve discovered.

It’s a good idea to practice presenting your findings to a group. If you pursue a scientific career, you’ll be doing just that after you follow the scientific method to learn more about your chosen field.

The scientific method is a solid procedure for discovering, evaluating, and researching the vast world around us. By implementing the steps, you improve your research skills and learn valuable information you can apply in many different ways.

The History of the Scientific Method

Have you ever wondered how scientists developed the steps needed to make discoveries? The history of the scientific method is fascinating.

Egyptian, Indian, and Babylonian scientists from thousands of years ago made notes and conducted experiments. But the scientists from ancient Greece actually developed some of the steps we recognize today as the scientific method.

Early philosophers of the time thought the way to arrive at knowledge through pure reasoning. They would observe the world around them, form conclusions, and then assume their conclusions must be correct.

Others, like Aristotle, saw the benefit of making detailed, systematic observations in order to build on known patterns and observations. This was quite different from Greek philosophers like Plato, who didn’t think observations were valuable because they thought the observable world was corrupt.

Aristotle’s method included:

1. Researching information others had already written on a subject.
2. Finding generally accepted ideas regarding a question on that subject.
3. Studying the subject systematically to gain more information.

Aristotle’s method was incomplete, however. It wasn’t really a scientific method, but it was a start.

Centuries later, men like Robert Grosseteste and Roger Bacon expanded these steps by emphasizing the importance of testing conclusions to see if they’re true, then making more observations and testing again. At that point, the scientific method was born.

With enough experimentation, a hypothesis can be confirmed as true. Then it becomes a theory, the next step in the scientific method.

And this is how scientists today broaden the knowledge in their fields. They stand on the shoulders of giants to see even farther and gain more understanding of the world today.

In our books and courses, you will find explanations of the scientific method and experiments which allow you to use the steps to learn more about the world around you through science.