The correct option is C.
Explanation
The neutron is a subatomic particle that, along with protons, constitutes the nucleus of an atom. Its discovery and physical properties are fundamental to understanding atomic structure and isotopes. Statement-wise Analysis:- Statement 1 is Incorrect: Neutrons were discovered by James Chadwick in 1932. J.J. Thomson is credited with the discovery of the electron in 1897 through his experiments with cathode ray tubes.
- Statement 2 is Incorrect: While neutrons are present in the nuclei of almost all atoms, the most common isotope of hydrogen, Protium (¹H), consists of only one proton and one electron, with no neutrons in its nucleus. Neutrons are present in other isotopes of hydrogen, such as Deuterium and Tritium.
- Statement 3 is Correct: A neutron is electrically neutral, carrying no charge. Its mass is approximately 1.6749 × 10⁻²⁷ kg, which is slightly greater than but nearly equal to the mass of a proton (1.6726 × 10⁻²⁷ kg).