Notice in the picture of sedimentary rocks, there is one layer on top of the other. The oldest rocks are on the bottom of the pile and the youngest or most recent rocks are on the top of the pile. This is known as the law or principle of

A) superposition.

B) horizontality.

C) uniformatarianism.

D) cross cutting relationships.

A. Superposition

Explanation:

A law of geochronology, stating that in any undisturbed sequence of rocks deposited in layers, the youngest layer is on top and the oldest on bottom, each layer being younger than the one beneath it and older than the one above it.

the number of valence electrons for each molecule or ion is shown beneath the structure. remember hydrogen will not have more than two electrons. this hydrogen is part of a covalent bond (sharing two electrons). a double bond here would cause hydrogen to share four electrons with phosphorus.