Answer
About 0.0055 moles of aluminum.
Work Step by Step
1. Find the volume of aluminum:
$V = 1.00cm^2 * 0.0550cm$
$V = 0.055cm^3$
2. Find the mass of aluminum, using the density:
$d = m\div v$
$2.699g/cm^3 = m \div 0.055cm^3$
$2.699 \times 0.055 = m$
$m \approx 0.1484g $
3. Find the number of moles of aluminum:
$mm = m \div nºmoles$
$26.98 = 0.1484 \div nºmoles$
$nºmoles = 0.1484 \div26.98$
$nºmoles \approx 0.0055 $