The modern periodic table, arranged in rows and columns, was first introduced by Dmitri Mendeleev in 1869. At the time, it included the known elements and their properties, but Mendeleev predicted ...

It looks like you're using an old browser. To access all of the content on Yr, we recommend that you update your browser. It looks like JavaScript is disabled in your browser. To access all the ...

It looks like you're using an old browser. To access all of the content on Yr, we recommend that you update your browser. It looks like JavaScript is disabled in your browser. To access all the ...

A landmark study reporting the discovery of Australopithecus africanus one century ago put the African continent at the centre of the story of humanity. Overcrowding can lead to disaster, and yet ...

After hours: 7 February at 18:05:20 GMT-5 ...