The word magic is not often used in the context of science. But in the early 1930s, scientists discovered that some atomic ...

Explain to students that in a hydrogen atom, the negatively charged electron is attracted to the positively charged proton. This attraction is what holds the atom together. Tell students that hydrogen ...

The question of where atoms come from requires a lot of physics to be answered completely – and even then, physicists only have good guesses to explain how some atoms are formed.

For example, you may have a card that says that the atom you are looking for has 5 neutrons. You would look at the periodic table to find an atom that you could add 5 to its number of protons that ...

The invisible dark matter is one of the universe's biggest mysteries, and its existence is confirmed only by the ...

An atom consists of a heavy center, called the nucleus, made of particles called protons and neutrons. An atom has lighter particles called electrons that you can think of as orbiting around the ...

When Israeli aircraft recently struck a uranium-enrichment complex in the nation, Iran could have been days away from ...

Because the mass of a proton is equivalent to a neutron, the relative mass of an atom is the same as its nucleon (mass) number. Neutrons have no charge. Protons are positively charged.

Chadwick discovers the neutron 1932. For four years, ... For example, a helium atom has an atomic mass of 4, but an atomic number (or positive charge) of 2. Since electrons have almost no mass, ...

Explore ETH Zurich’s cutting-edge experiments on fundamental forces and dark matter. Click to read the full story now ...