what is the above mentioned substance?
It is a subatomic particle, symbol or , which has a neutral charge.
Neutron
The neutron is a subatomic particle, symbol or , which has a neutral (not positive or negative) charge and a mass slightly greater than that of a proton. Protons and neutrons constitute the nuclei of atoms. Since protons and neutrons behave similarly within the nucleus, and each has a mass of approximately one atomic mass unit, they are both referred to as nucleons. Their properties and interactions are described by nuclear physics.
The chemical properties of an atom are mostly determined by the configuration of electrons that orbit the atom's heavy nucleus. The electron configuration is determined by the charge of the nucleus, set by the number of protons, or atomic number. Neutrons do not affect the electron configuration, but the sum of atomic number and the number of neutrons, or neutron number, is the mass of the nucleus.
who provided evidence to suggest the existence of the neutron James Chadwick.
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Neutron [SEP] Introduction
The neutron is a subatomic particle, symbol or , which has a neutral (not positive or negative) charge and a mass slightly greater than that of a proton. Protons and neutrons constitute the nuclei of atoms. Since protons and neutrons behave similarly within the nucleus, and each has a mass of approximately one atomic mass unit, they are both referred to as nucleons. Their properties and interactions are described by nuclear physics. The chemical properties of an atom are mostly determined by the configuration of electrons that orbit the atom's heavy nucleus. The electron configuration is determined by the charge of the nucleus, set by the number of protons, or atomic number.