If you consider the equation, E=mc2, you can see that an amount of mass can be considered as equal to an amount of energy. In other words, we could take all the mass in a nuclear reaction and figure out how much energy that represents. If you add that to the amount of energy present at the same time, you get a summation of energy (some of which is mass represented as energy). That amount of energy does not change in a nuclear reaction.
the number of protons and neutrons
During a nuclear fission reaction, products such as two or more lighter nuclei, neutrons, gamma rays, and energy are given off. These products can vary depending on the specific isotopes involved in the reaction.
A gas released during a chemical reaction is a chemical change.
helium-4
The enthalpy of a chemical reaction is the change of heat during this reaction.
The subatomic particles that can change in a nuclear reaction are protons, neutrons, and electrons. During nuclear reactions, these particles can be gained or lost, leading to the formation of different elements and isotopes.
the number of protons and neutrons
In the nuclear fusion process in the sun, two protons change into a proton and a neutron, plus also a positron and a neutrino. This is part of the synthesis of helium and release of energy which powers the sun. You can see the complete chain of reaction at the link below
Yes. Very much. That is how we get useful heat to make steam, to turn turbines, to make electricity.
No, mass does not increase during a nuclear change. According to the principle of mass-energy equivalence (E=mc^2), the mass of the reactants is converted into energy during a nuclear change.
Radiation
what colour change occurs during the calcium and hydrochloric acid reaction
A catalyst undergoes no chemical change during a chemical reaction.
subatonic particles
"Substance" is too fuzzy a word. Chemical reactions can change materials into other compounds, for example shiny iron into rust (Fe2O3). But it cannot change an element into another element. A nuclear reaction can do that, for example uranium into plutonium.
During a nuclear fission reaction, products such as two or more lighter nuclei, neutrons, gamma rays, and energy are given off. These products can vary depending on the specific isotopes involved in the reaction.
The enthalpy of a chemical reaction is the change of heat during this reaction.