What does the Y looking letter means and what's it's value in the nuclear equation?

There is an area in idaho named craters of the moon where most of the ground is covered with basalt, adark gray, igneous rock with no visibl crystals. what can you infer about the geographical history of the area?

Select all of the statements which are true. electrons are located in shells or orbits around the atom. electrons orbit slowly around the atom. electrons travel in one flat path around the nucleus of an atom. the valence of an atom is determined by the number of electrons in the atom's outermost shell.

Citric acid has a ph between 1 and 3.  it is considered to be aa. weak acidb. weak basec. strong based. strong acid