When building an atom, pay close attention to the particles' electrical charges. Protons have a charge of +1. Electrons have a charge of -1. Neutrons are neutral, as its name implies. A stable ...

An inner electron in a low energy level can rise ... The different black lines show the frequencies absorbed by electrons in atoms. An excited electron can fall to a lower energy level.

Atoms increase in size. This is because of the screening effect of the filled inner electron levels. These electrons screen or shield the outer electrons from the nuclear charge.

The flux of electrons is represented by red arrows and e-, and the flux of protons is represented by red arrows and H ...