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 a crystalline, while the other is amorphous. It is your job to determine which one is amorphous because 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. Determine the density of each cube. The less dense cube is the amorphous solid.

C. 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.

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.

This is what it said when I had answered: "C"

Feedback:

While melting the cubes would help you determine which is which, it would destroy the atomic geometry, so the differences would disappear when you cooled them down to the solid form again.

Should the answer be "B" then??

The answer was B

Personally I think this is a flawed question. It did NOT ask to determine which was which by a process in with the state was not modified; it asked to determine which was which and the melting point (broad for amorphous and sharper for crystalline) works very well. The fact that melting the amorphous solid allows it to crystallize when cooled is beside the point. And you wouldn't need the entire cube to determine the melting ont this way; only a very small amount would be necessary. So the question really has two answers; perhaps I should say the answers are flawed and the question is ok.

I will send a msg to the site & see what I receive back. I figure that D should have been correct initially, but I picked C instead by accident...it came up with the feedback stmt & I got more confused.

The answer is B.

No, the answer should be D.

Determining the density of the cubes (option A and option B) is not an effective method because the density of a material does not necessarily correlate with its structure. Both crystalline and amorphous materials can have a wide range of densities depending on their composition.

The correct method to determine which cube is amorphous is to melt both cubes and measure the range of melting temperatures (option D). Amorphous materials typically have a broader melting temperature range compared to crystalline materials.

When a crystalline solid melts, it does so at a specific temperature, whereas an amorphous solid softens and becomes a liquid over a range of temperatures. By measuring the range of melting temperatures, you can identify the cube that melts over a narrower range as the crystalline one, while the one that melts over a broader range is the amorphous solid.

It's important to note that melting the cubes will indeed destroy their atomic geometry, but in this specific case, you are asked to identify the amorphous cube based on its melting behavior, not to retain their original structure.