Answer:
The hardness rating is 4.
Explanation:
Calcite sits at a hardness rating of 3 and is very easily scratched with a knife and/copper coin. This is where most Marbles, limestones, travertines, rate.
Meanwhile, Fluorite sits at hardness 4 and can be scratched by a knife.
Sidney W. Fox produced proteinoid spheres, which suggest a possible route from chemical to cellular life.
Answer:
Index Fossils
Explanation:
Index fossils are used by scientists to help them figure out the dating of discovered fossils or the correlation. They are also very known to appear in a (very) certain/specific age range.
Hope this Helps!
Answer:
pathogens
Explanation:
pathogens may occur in various way e.g spread from a person to person by directly body contact
