Therefore, electrons cannot be arranged at random, but they must have fixed levels of energy within each type of atom. Bohr's 'solar system' model of the atom is the way that most people think ...

It also tells us that chlorine has 18 neutrons (35 - 17) and, as the number of electrons and protons are equal in a neutral atom, chlorine also has 17 electrons. The relative mass of a nucleus is ...

The idea was first cooked up in 1969 after a scientist named Roger Penrose noticed that a particle getting close to a spinning black hole gained energy. New Scientist adds that another scientist, ...

He discovered the atomic nucleus and developed a model of the atom that was similar to the solar system. Like planets, electrons orbited a central, sun-like nucleus. Acceptance of this model grew ...

Thus when an atom absorbs or gives off energy (as in light ... But there was good evidence he was right: the electrons in his model lined up with the regular patterns (spectral series) of light ...