15.1 Electric Charge and the Electrical Structure of Matter Fundamental Law of Electric Charge:         Opposite electric charges attract each other. Similar electric charges repel each other. A Simple Model of the Structure of Matter 1. All matter is composed of sub-microscopic particles, called atoms. 2. Electric charges are carried by particles within each atom that are called electrons and protons. 3. Protons are found in a small central region of the atom, called the nucleus. They are small, heavy …showed first 75 words of 1675 total…

…showed last 75 words of 1675 total…a lower wavelength. D. Gamma Radiation There three distinct types of radioactive materials: 1) a type of particle similar to high-speed helium nuclei, with poor penetrating power, called alpha particles. 2) a type of particle similar to high speed electrons, with the ability to penetrate up to several millimeters of aluminum, called beta particles . 3) a form of radiation, similar to very high energy X-rays, with the ability to penetrate even several centimetres of lead, called gamma rays .