The “lead” of a pencil is actually made of a substance called graphite which is made of carbon atoms. The picture shows a close-up of one carbon atom. A hydrogen atom has one proton as the nucleus and ...

Protons have a charge of +1. Electrons have a charge of -1. Neutrons are neutral, as its name implies. A stable atom has a net charge of 0. In other words, it has an equal number of protons and ...

Since electrons have almost no mass, it seemed that something besides the protons in the nucleus were adding to the mass. One leading explanation was that there were electrons and additional ...

This technique involves injecting a malignant tumour with non-radioactive boron ... with the neutrons, triggering the release of high-energy alpha particles, comprising two protons and two ...