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.
Well basically rotation causes Night and Day. The earth tilts on a 23.5 degree tilt and that is also a big part of day and night. Seasons are also affected by the tilt. When the earth is tilted towards the sun, it’s summer when it’s tilted away from the sun, it’s winter
Echinoderms are most closely related to chordates because both are: <span>D)Ectotherms</span>