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The Periodic Table of Elements

The Periodic Table of Elements can be daunting to look at. To many, the letters and numbers run together, creating a meaningless mass on a page. However, the periodic table actually represents an ordered organization of each known element on earth.

Elements are substances composed of only one kind of atom, and currently we have identified 118 elements. These elements are what make up everything around you, though they are usually found in compounds, such as water, which is made of hydrogen and oxygen atoms.

Until 1869, the elements had not been given any kind of order. Russian chemist Dmitri Mendeleev suggested the numbers be organized by increasing atomic weight and chemical characteristics. According to Mendeleev:

“I began to look about and write down the elements with their atomic weights and typical properties, analogous elements and like atomic weights on separate cards, and this soon convinced me that the properties of elements are in periodic dependence upon their atomic weights.”
, Principles of Chemistry, 1905, Vol. II

The elements on the periodic table are organized in rows and columns, called periods and groups respectively. Elements in the same row have the same number of orbitals, while element in the same group have the same number of valence electrons.

Other information can be found on the periodic table, such as the atomic number, which tells how many protons are in the nucleus, the mass number, which tells how many protons and neutrons are in the nucleus, and the chemical symbols. Some charts offer more information, including the spin of electrons in the orbitals, melting and boiling points, and the abundance of the element in the universe.

Information found on the periodic table can tell you a lot about how different elements react to one another. With a strong grasp on how chemical reactions work, you can predict how elements will bond and form compounds.

Want more information about the elements, physical science, and how the world works? Explore You Can Learn’s Seven Incredible Concepts in Physical Science course to find out more about the forces that hold the universe together every second of every day!