# Element Density of Period 2

1. Oct 24, 2008

### ncm2

1. The problem statement, all variables and given/known data
Which of the elements, from the second period, has the highest density in its standard state?

2. Relevant equations
Standard state is gas at 1 atm, concentration of 1 M for liquid, or pure substance at 25C and 1 atm.

3. The attempt at a solution
I thought that N, O, F, and Ne could be removed from possibilities because they are gases. Then I looked it up and found Boron had the largest density, but that was incorrect.

2. Oct 24, 2008

### Redbelly98

Staff Emeritus
What did you find for densities for all the solids in that period?

3. Oct 24, 2008

### ncm2

I found:
Li: .534 g/cm^3
Be: 1.85 g/cm^3
B: 2.34 g/cm^3
C: 2.267 g/cm^3
N: .00125 g/cm^3
O: .00149 g/cm^3
F: .001696 g/cm^3
Ne: .0008999 g/cm^3

4. Oct 25, 2008

### Staff: Mentor

I would say boron in the standard state is the densest.

There is a little catch here - diamond (which is a pure carbon) has much higher denisty, something like 3.5 g/mL. But diamonds are not thermodynamically stable - they convert to graphite. Conversion is so slow, that for all practical purposes diamonds are stable - but thermodynamically they are not. Thus they are not standard state of the carbon.