February 7 is National Periodic Table Day, when we celebrate the efforts of scientists over the centuries to figure out how different elements ...

On 17 February 1869, Russian chemist Dmitri Mendeleev jotted down the symbols for the chemical elements, putting them in order according to their atomic weights and inventing the periodic table.

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 ...

1. Periodic Table as Arranged by Mendelejeff attention to the fact that “the eighth element, starting from a given one, is a kind of repetition of the first, like the eighth note of an octave in ...

There is a new exhibit at the University of Arizona Flandrau Science Center and Planetarium: Universe of Science. It features ...

They are seeking good fortune in their hunt for an elusive entity: element 119. The periodic table looks complete, but it isn’t. The race is on to discover the table’s next row of elements ...

Artist's concept of the signal (r.) occurring during measurement of resonant inelastic X-ray scattering in samples containing ...

How do we calculate mass and atomic numbers? VideoHow do we calculate mass and atomic numbers? This video is an interactive lesson in calculating an atom's mass and atomic number.

“New Horizons shattered a major paradigm of planetary science,” says Alan Stern, the mission’s principal investigator. “Pluto ...

D espite accounting for around 0.025 percent of all mass on the planet, carbon is vital for life on Earth. This element, ...

These are the best STEM toys for children of all ages. Shop editor and expert loved chemistry sets, circuit boards, ...