Read the paragraph, and then answer the question. Coal is a black, hard substance formed from the remains of living things that existed a long time ago. The remains were buried and exposed to pressure and temperature underneath Earth’s surface. Over time, these remains solidified.

Which of the spheres interact in the formation of coal? Check all that apply.

atmosphere
biosphere
cryosphere
geosphere
hydrosphere

The coefficient of friction is a number that represents the resistance to sliding between two in contact with one another.

Aphase diagram assumes is kept constant.

You are a researcher for a golf club manufacturer. you are given two identical looking cubes of a metal alloy. you are informed that they are made of the exact same material, but one is crystalline, whereas the other is amorphous. it is your job to determine which one is amorphous this one is more stress-resistant and is useful in reinforcing golf clubs. which of the following is the best way to determine which is which? a. determine the density of each cube. the more dense one is the amorphous solid. b. melt both cubes and look for a broader range of melting temperatures. the one that melts over a broader range of temperatures is the amorphous solid. c. determine the density of each cube. the less dense cube is the amorphous solid. d. melt both cubes and measure the range of melting temperatures. the one that melts over a narrower range of temperatures is the amorphous solid.