The answer is the el second one since it is a physical change
Answer:
D i think, sorry if its wrong
Explanation:
<span>The behavior, or reactivity, of elements in a group, or family will behave similarly because they have the same numbers of valence electrons. An example might be the alkali metals (with the exception of hydrogen, H, which is a gas) which form +1 ions in their compounds, have a relatively low melting point, and react violently with water. Other groups of atoms also show similar properties although different from the alkali metals. This type of behavior is one of the things that helps us categorize the elements into the periodic table of the elements. Mendeleev noticed similarities in the behavior of certain elements that originally allowed him to place them into families and develop that periodic chart</span>
Answer:
Chain reaction
Explanation:
A chain reaction is a process by which neutrons that have been released in a first nuclear fission produce an additional fission in at least one more nucleus. This atomic nucleus fishes and releases more neutrons, giving the opportunity to repeat the process.
Nuclear fission is the physical-chemical reaction through which the nucleus of an atom is split. In the main interest of fission reactions is that through this operation a large amount of energy is obtained. According to the definition of nuclear energy, atomic energy is the energy contained in the nucleus of an atom and the energy obtained is thermal energy, energy in the form of heat.
The other form of exploitation is through nuclear fusion reactions. In this case, the process is reverse, merging two different nuclei forming a single atomic nucleus.
After fission of the atomic nucleus we obtain various fragments with a mass almost equal to half of the original mass plus two or three neutrons. It is remarkable the release of these two or three neutrons because they are what will allow a new reaction in another atom.
