The periodic table of elements was first proposed by Russian Dmitri Mendeleev in 1869. The periodic table was a culmination of work done by other scientists prior to Mendeleev. For decades scientists looked for a better method of grouping and arranging the elements. It wasn't until 1829 that a scientist by the name of Johann Wolfgang Dobereiner found that many of the elements could be grouped together based on their chemical properties. These groups he called triads. It wasn't until the 1860's when Dimitri Mendeleev proposed his version of the periodic table, which was the first widely recognized periodic table. In contrast to the older versions of the periodic table Mendeleev was inspired to organize the elements in rows and columns. One of the scientists who had previously attempted this was Antoine Lavoisier. He arranged the elements based on their properties such as gases, non-gases, metals, non-metals and earths. After publishing his table, Mendeleev predicted the discovery of other elements and allowed spaces in the table for those elements that hadn't been discovered yet. He was quoted as saying "I saw in a dream a table where all the elements fell into place as required. Awakening, I immediately wrote it down on a piece of paper." and "We must expect the discovery of many as yet unknown elements...[2]." With Mendeleev's periodic table and years of research and experimentation, the periodic table we know today was born.
Periodic Table Patterns and Using Its Information
To the average person the periodic table is not much more than a fancy layout of all the known elements. But to chemists, biologist, and those interested, the periodic table is a fountain of information. Some of the information found in the periodic table includes: atomic number, atomic radii, electron configuration, and other chemical properties.
One of the most prominent features of the periodic table is the often colorized organization of all the chemical elements. As you can see in the picture below the elements are collected into groups and given a color to represent their similar characteristics. Many periodic tables such as this one provides a key to label the different colors identifying what group of elements it is.
Another feature illustrated in the periodic table below are the numbers along the top and left hand side representing the columns and rows of the periodic table. These columns and rows, often called groups and periods,of the periodic table present common characteristics or trends within them. [1] Each of the columns of the periodic table represent a series of elements with increasing atomic radii. As you go down the column thay have common chemical characteristics to one another. A good example of this is to look at the Alkali metals in the first column. All of these elements have one electron in their outer shell giving them all very similar chemical characteristics and reactivity. In addition to grouping by similar characteristics you can also use the position of the element to determine its orbitals. Orbital refers to the path the electron follows around the atom. The position on the table explains where the electrons in the atom of the element lie. Column 1 and 2 have their outermost electrons in what is called the s orbital. Columns 3-12 have theirs in the d orbital; except for the lanthanides and actinides which are typically depicted separately below the main table which have f orbitals for their outermost shell. This grouping is done because they still share most of the same characteristics as that column but have a different outermost orbital. Finally there are columns 13-18 which has the p orbital elements.
Somewhat similar to the columns are the rows of the periodic table. Instead of showing similar chemical characteristics they show trends in characteristics such as electronegativity, atomic radii, electron affinity, and ionization energies.
[3]
So What Do we need it for?
-The table can be used to predict properties of elements that have not been discovered
-The table makes trends in element properties more apparent
-Combines man-made and naturally occuring elements in a single place. [1]
Periodic Table
History of the Periodic Table
The periodic table of elements was first proposed by Russian Dmitri Mendeleev in 1869. The periodic table was a culmination of work done by other scientists prior to Mendeleev. For decades scientists looked for a better method of grouping and arranging the elements. It wasn't until 1829 that a scientist by the name of Johann Wolfgang Dobereiner found that many of the elements could be grouped together based on their chemical properties. These groups he called triads. It wasn't until the 1860's when Dimitri Mendeleev proposed his version of the periodic table, which was the first widely recognized periodic table. In contrast to the older versions of the periodic table Mendeleev was inspired to organize the elements in rows and columns. One of the scientists who had previously attempted this was Antoine Lavoisier. He arranged the elements based on their properties such as gases, non-gases, metals, non-metals and earths. After publishing his table, Mendeleev predicted the discovery of other elements and allowed spaces in the table for those elements that hadn't been discovered yet. He was quoted as saying "I saw in a dream a table where all the elements fell into place as required. Awakening, I immediately wrote it down on a piece of paper." and "We must expect the discovery of many as yet unknown elements...[2]." WithMendeleev's periodic table and years of research and experimentation, the periodic table we know today was born.
Periodic Table Patterns and Using Its Information
To the average person the periodic table is not much more than a fancy layout of all the known elements. But to chemists, biologist, and those interested, the periodic table is a fountain of information. Some of the information found in the periodic table includes: atomic number, atomic radii, electron configuration, and other chemical properties.One of the most prominent features of the periodic table is the often colorized organization of all the chemical elements. As you can see in the picture below the elements are collected into groups and given a color to represent their similar characteristics. Many periodic tables such as this one provides a key to label the different colors identifying what group of elements it is.
Another feature illustrated in the periodic table below are the numbers along the top and left hand side representing the columns and rows of the periodic table. These columns and rows, often called groups and periods,of the periodic table present common characteristics or trends within them. [1] Each of the columns of the periodic table represent a series of elements with increasing atomic radii. As you go down the column thay have common chemical characteristics to one another. A good example of this is to look at the Alkali metals in the first column. All of these elements have one electron in their outer shell giving them all very similar chemical characteristics and reactivity. In addition to grouping by similar characteristics you can also use the position of the element to determine its orbitals. Orbital refers to the path the electron follows around the atom. The position on the table explains where the electrons in the atom of the element lie. Column 1 and 2 have their outermost electrons in what is called the s orbital. Columns 3-12 have theirs in the d orbital; except for the lanthanides and actinides which are typically depicted separately below the main table which have f orbitals for their outermost shell. This grouping is done because they still share most of the same characteristics as that column but have a different outermost orbital. Finally there are columns 13-18 which has the p orbital elements.
Somewhat similar to the columns are the rows of the periodic table. Instead of showing similar chemical characteristics they show trends in characteristics such as electronegativity, atomic radii, electron affinity, and ionization energies.
[3]
So What Do we need it for?
-The table can be used to predict properties of elements that have not been discovered-The table makes trends in element properties more apparent
-Combines man-made and naturally occuring elements in a single place. [1]
1. "Why is the Periodic Table Important." Anne Marie Helmenstein Ph.D., ThoughtCo.com, https://www.thoughtco.com/why-is-the-periodic-table-important-608829. July 15, 2017.
2. "Dimitri Mendeleev quotes and sayings." Inspiringquotes.us, https://www.inspiringquotes.us/author/2671-dmitri-mendeleev. July 15, 2017.
3. Picture Above taken from http://www.ptable.com/Images/periodic%20table.png