These are almost one-quarter of the periodic table and are mainly found in the first four periods. Of these, 11 are essential elements that our bodies need in larger amounts: oxygen, carbon ...

The periodic table of elements is a landmark categorization developed in 1869 by the Russian chemist and inventor Dmitri Mendeleev. It arranges all natural and synthetic elements by their atomic ...

An 1869 MIT entrance exam paper has gone viral after being shared on Reddit, with many users deeming it easy. Massachusetts Institute of Technology’s (MIT) entrance paper for 1869-1870 has gone ...