Answer:
D. The nucleus of an atom of lithium splits, resulting in smaller fragments and the release of a large amount of energy.
Explanation:
Fission is the splitting of a nucleus, so this is the only option that involves fission.
A is wrong. Li atoms do not bond to form molecules. Instead, the nuclei are immersed in a sea of electrons.
B is wrong. The joining of two nuclei is fusion.
C is wrong. Adding an electron to an atom of lithium is not a nuclear reaction.
Event 1 is an example of a chemical reaction.
<u>Explanation:</u>
Whenever there is a chemical reaction, we can find that by means of a color change, formation of any gas, vapors, bubbles or any color or colorless precipitation, or by means of heat generation.
In the event 1 there is only a clear liquid in the beaker again it is added to a clear liquid in another beaker, forming an orange colored liquid , which shows that there is an occurrence of some chemical reaction.
So Event 1 is most likely an example of a chemical reaction.