The appearance of fossils would the the answer.
Although there has been some scientific debate about what fossil strata should mark the beginning of this period, the "International Geological Congress" determined that the Cambrian period was approximately 543 million years ago of which the first appearance in the fossil record of worms that made horizontal burrows was discovered.
Solutions that have more or greater concentration of hydroxide ions (OH-) than hydrogen ions (H+) are basic or alkali in nature. They showcase the properties of a base and not of an acid.
A scientific law describes a behavior of something that occurs
Explanation:
To dissolve, solvent particles must come in contact with solvent particles. Particles of hot water are moving much more rapidly than particles of cold water. Hence, in hot water more water particles will come in contact with hot chocolate powder than in cold water, resulting in faster dissolving.
Thermodynamics is the study of energy and it changing forms, hope this helps.