The rocker pivot pin that holds the valve/pushrod rocker in place could be loose. If the shaft it not locked in place, it can turn in the hole. this will cause a high pitched squeak. The shaft can NOT fall out, there is not enough room. I do not know if that is the problem. I did experience this with a 1989 sporty If you are mechanically inclined: Deturmine which cylinder is making the noise. Remove rocker box cover only. (Four 1/4-20 cap screws) slide cover to one side or the other and see if there is discoloration the the area around the pivot pin. If the parts are blueish in color, that would be the area of interest.
A standard chemical reaction always and only involves a change in the electron configuration of the atom (either the number of electrons or their energy configuration). If the nucleus is affected (either the number of protons or electrons), then it is designated as a nuclear reaction, and this is quite different.
Any element in the first column (Group 1) of the periodic table will react violently with water. They get more explosive as you go down the column, so that means lithium, sodium, potassium, rubidium, caesium and francium will be more reactive, in that order. The elements in the second column (Group2) react less violently with water. And like the Group 1 elements, their reactivity increases as we go down the column.
When added to water the Group 1 elements, the Alkali metals, becomes a +1 ion, and the water forms OH- (creating the metal hydroxide) and H2 gas. Group 2 elements, the Alkaline earth metals, become a +2 ion, and combine to make (OH)2 metal hydroxides.
Sir Humphrey Davy was the discoverer of the elements potassium, sodium and several others. He was a chemist and inventor who lived 1778-1829. He developed the study of electrochemistry. He also invented practical things such as the miners' safety lamp.