What are ancient plants and animal formed into rocks called it is a 7 letter word that starts with f

Fossils

Explanation:

Ancient plants and animal formed into rocks called fossils.

A fossil can be defined as the mineral impression or remains of living organisms such as plants and animals that are prehistoric in nature.

A geologic column can be defined as a collection of rock layers that are typically grouped based on their relative ages in a descending order i.e from oldest to the youngest.

Generally, the layers of the rock that are found in various parts of the world are known to be different because they all comprises of distinct Earth's geological history (fossils).

answer; i believe the correct answer is (solid gold);

the electrical  conductivity  of asolution  of an electrolyte is measured by determining the resistance of thesolution  between two flat or cylindrical electrodes separated by a fixed distance.