txlonghorn2314

5+ Year Member
Jan 22, 2013
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Pre-Medical, Medical Student (Accepted)

There is a chart that lists certain properties of elements at 25ºC, and it shows that the density of manganese is 7.43g/cm3

What is the density of manganese at 1000°C?

A. Between1.00 and 2.00
B. Between 2.00 and 7.43
C. Between 7.43 and 9.00

D. Between 9.00 and12.00

I knew that B was the better answer, but just wanted some clarification as to why I would rule out option A.

The temperature increases, so the volume increases which lowers the density, so it is obviously not C or D. But because 7.43g/cm3 is its density at 25ºC, and since 1000ºC is a drastic increase in temperature, I felt like the density could have been decreased drastically to below 2. Is there something more concrete as to why I would rule this out, or is this just a judgement "pick the better answer choice" type problem.
 

Cawolf

Medical Student
5+ Year Member
Feb 27, 2013
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Medical Student
I remember thinking about that question when I saw it.

My logic was that we know the density will decrease, but with the information we have, we can only say it will be less than 7.43 - but not how much less.

That rules out choice A because we are stating that we know the density will be a maximum of 2 - when we only can say it will be less than 7.43. That makes choice B the only reasonable choice.
 
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