The correct answer is: A. Electrons
Electrons are negatively charged particles that move around the nucleus of an atom. They are much smaller than protons or neutrons, and they have a negative charge of -1. Electrons are found in shells around the nucleus, and each shell can hold a certain number of electrons. The outermost shell is called the valence shell, and
it is the shell that determines the chemical properties of an atom.Protons are positively
charged particles that are found in the nucleus of an atom. They have a mass that is about 1836 times the mass of an electron, and they have a positive charge of +1. Protons and neutrons are held together in the nucleus by the strong force.Neutrons are neutral particles that are found in the nucleus of an atom. They have a mass that is about 1836 times the mass of an electron, and they have no charge. Neutrons are thought to be made up of quarks.
Positrons are positively charged particles that are the antiparticles of electrons. They have a mass that is the same as the mass of an electron, and they have a positive charge of +1. Positrons are created in nuclear reactions, and they can also be created by high-energy photons.