The Periodic Table of Elements

The Table of elements was started by Johann Dodereiner, a German chemist. He made the Law of Triads. The Law of Triads is when you add the atomic weight of elements that are similar and will add up to the third. This was the first try to group elements. 

In 1862, Alexandre Beguyer de Chancourtois, a French geologist, published the first table. The table had columns around the circumference of a cylinder.

In 1863, John Newlands, an English chemist, published the table with elements in the order of increasing atomic weight but because he didn’t allow space for new elements it was criticized.  

In 1864, Lothar Meyer published a table that described how the elements were placed. He grouped them by their properties. This was the first time someone tried to group the elements by the properties.

After five years, Dmitri Mendeleev challenged himself to rearrange the Table of Elements. He arranged them by the atomic weight and properties. He left several spaces for new elements.

Later on in 1913, Henry Moseley used the X-ray and found that the wavelength of X-radiation of the element decreased with increasing atomic weight, because of the he assigned a new set of numbers to the elements. The new set of numbers is called atomic number. The atomic number is the number of protons or positive charges, contained in the atomic nucleus. There are also electrons which are the negative charge, it is the neutral atom. To find the number of electrons you have to take the atomic weight and subtract it from the atomic number. Now there are many different types of periodic tables such as the cylinder, spiral and much more!

The Periodic Table- powerpoint

Just a little writing project I had to do at school.

Advertisements

4 responses to “The Periodic Table of Elements

  1. I like the fact that while this is the history of the periodic table as we knew it when I was growing up, there are new ways of showing the information like the spiral table. Science is the way we describe our world and while the
    way world works doesn’t change, we change the way we describe it.

  2. heh heh very scientifical! i didn’t know anything except for the dmitri guy…

  3. Very nice writing! I didn’t know there was such a long history behind the periodic table. Do you think you can find pictures of what the periodic table looked like along its history of development? If so, it might help many of us visualize its course of changes.

    Thank you very much for sharing your school work with us! I learned something new 🙂

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s