After 1950, when the previous edition was published, advancing technology made possible a great deal of experimental work on the properties of negative ions in gases. Photodetachment techniques became ...

Sodium becomes a positive ion and chlorine becomes a negative ion. The positive and negative ions attract each other and form the ionic compound sodium chloride. A sodium and chlorine atom are near ...

The European Space Agency’s (ESA) Negative Ions at the Lunar Surface (NILS) instrument, carried by Chang’e-6, detected negative ions on the lunar surface, produced by interactions with the ...