Only emission of a gamma ray alone without an alpha or beta particle. Different energy states of the same isotope are called isomers. See link below
Yes, it is possible; disintegration is not considered a nuclear reaction.
Hydrogen is an element. You cannot change one element to another without a nuclear reaction. However, hydrogen gas can be changed to liquid hydrogen by compressing and cooling it. Liquid changes to gas by releasing pressure, and warming it.
Neptunium is an artificial element; but significant amounts of neptunium are gathered in nuclear wastes from nuclear reactors, now without uses.
Enzymes, as used in reactions, usually do not causes bond formation. They are usually responsible for breaking of bonds but when used in bond formation, they are commonly catalysts. Catalysts simply provide a lower activation energy and causes the reaction to occur faster. Thus, without catalysts, the reaction (including bond formation) will still occur, just at a slower rater. Thus, bond formation can definitely occur without enzymes (catalysts).
The reason a nuclear chain reaction occurs is that one of the by products of a single reaction: the neutrons can start reactions of their own. So how do you stop a chain reaction? Stop these neutrons from causing any more reactions. This is done in nuclear reactors by placing control rods into the reactor core. These control rods are made of elements that can absorb the high energy neutrons without reacting themselves. Therefore, by moving these rods in and out of the reactor, the rate of reaction in a nuclear reactor can be easily controlled.
Carbon isn't a mixture. It's an element. It's already present without a reaction.
Can not. Elements can not be changed into other elements by chemical reactions. Elements changing into other elements requires an atomic reaction, like nuclear fusion.
There's no such thing as a bad element. Take arsenic, for instance. It is very poisonous so you might call it a bad element. But you can't make silicon chips or LEDs without arsenic, so it's a good element. Plutonium is another one. They make nuclear bombs out of it. Bad element? Not if you're fueling your nuclear reactor with it and powering a city with the electricity.
The only element needed to start nuclear fission is Uranium-235, which is very slightly radioactive but when made into fuel rods and before any use in a reactor can be handled without danger.
Because an element in itself is defined as the simplest form of any substance found on earth. So you cant take a simplest form of a fraction and make it smaller without changing it.
Scientists centuries ago believed that a nuclear reaction which was very large would be capable of producing the energy of the sun, they thought this because when they experimented with nuclear reactions and measuring the energy produced the reaction of coal not burning long without being consumed.
If it is possible without any other nuclear reactions to be done, it'll give you an isotope of iridium.