Finding molar mass from gas density at 1000°C and 10 torr

[Bashyboy]

Homework Statement

At 1000 deg C and 10 torr, the densit of a certain element in the gaseous state is 2.55×10^-3 g/L. The element is:

Homework Equations

The Attempt at a Solution

So, i took the the density equation, that of which is derived from the ideal gas law, and rearranged to solve for the molar mass, but, unfortunately, it did not suceed. What am I to do to solve this problem?

 

[Borek]

What molar mass did you get?

 

[Bashyboy]

I got 21 g/mol--which is the answer. Sorry, i was looking at the wrong answer