Many heavy atoms form from a supernova explosion, the remnants of which are shown in this image. NASA/ESA/Hubble Heritage ...

By the middle of the twentieth century we’d understood how chemical elements were made up of protons, neutrons and electrons.

The precursors of heavy elements might arise in the plasma underbellies of swollen stars or in smoldering stellar corpses.

Richard Feynman, a famous theoretical physicist who won the Nobel Prize, said that if he could pass on only one piece of ...

two neutrons and two electrons. Of course, on Earth there are lots of atoms besides these that are just as common, such as ...

Curious Kids is a series for children of all ages. If you have a question you'd like an expert to answer, send it to ... .</ ...

So why do so many life-forms breathe oxygen?There are probably thousands of kinds of metabolisms, or chemical processes that maintain life, said Donald Canfield, a geobiologist at the University of ...

Take, for example, vitamin B12. It is made of six different elements: carbon, hydrogen, nitrogen, oxygen, cobalt, and phosphorus.

In 1871, a hot-tempered Russian scientist called Dmitri Mendeleev laid out the most effective grouping of chemical elements. These groupings, which allegedly came to Mendeleev in a dream, organize ...

Key Concepts The periodic table is a chart containing information about the atoms that make up all matter. An element is a substance made up of only one type of atom. The atomic number of an atom is ...

Have students look at their Periodic table of energy levels for elements 1–20 distributed in lesson 3. Explain that the two electrons in the hydrogen molecule (H 2) can be thought of as “belonging” to ...