# Chemistry (Check)

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classify each of these statements as always true, sometimes true, or never true.

__ST___11)The unit of a conversion factor must cancel.
__AT___12)the conversion factor for changing grams and milligrams is 1g/1000mg
___ST__13)multiple conversions factors can be used to solve complex conversion problems.
___NT____14)if density=mass/volume, then mass= density/volume.
____NT_____15)when two measurements are equal, a ratio of these two measurements will equal unity.

14 is ok.
15 is not. If two measurements are equal, for example one measurement is 14 and the other is 14, then 14/14 = 1, nicht wahr?
11. Confusing to me. I don't know that they MUST cancel. It depends upon what is being done.
12. Again I am confused. As it is written with grams AND milligrams, the factor 1g/1000 mg is ok but it might be the inverted form in some cases.
The factor IS 1/1000
13. I tend to think multiple conversion factors will always work if we can find the factors.

I hope this helps a little.