Question 6 4 pts
6) Chromium crystallizes in a body-centered cubic unit cell. If the length of an edge of the unit cell
is 289 pm, what is the density (in g/cm3) of chromium?
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7.15g/cm³

Explanation:

To solve this question we must know that a body-centered cubic unit cell contains 2 atoms.

The volume of the unit cell is:

289pm = (289x10⁻¹²m)³ =

2.414x10⁻²⁹m³ * (1cm³ / 1x10⁻⁶m³) = 2.414x10⁻²³cm³

And the mass is -Molar mass Chromium = 51.9961g/mol:

2atoms * (1mol / 6.022x10²³atoms) * (51.9961g / mol) =

1.727x10⁻²²g

The density is:

1.727x10⁻²²g / 2.414x10⁻²³cm³ =

aquifers are bounded above and below by impermeable rock. the driving force of groundwater movement in confined aquifers is pressure, rather than gravity.