* Protons: The atomic number of an element defines the number of protons in its nucleus. Indium (In) has an atomic number of 49. Therefore, a neutral indium atom has 49 protons.
* Electrons: In a neutral atom, the number of electrons is equal to the number of protons. So, a neutral indium atom has 49 electrons.
* Neutrons: The mass number of an isotope represents the total number of protons and neutrons. Indium-113 has a mass number of 113. To find the number of neutrons, subtract the number of protons from the mass number: 113 - 49 = 64 neutrons.
Summary:
* Protons: 49
* Neutrons: 64
* Electrons: 49
