A lead atom has a mass of 3.4⋅10^-22 g. How many lead atoms are in a cube of lead that has a volume of 2.07 cm^3 if the density of lead is 11.3 g/cm^3?

volume = 2.07 cc

density = 11.3
mass = volume x density = 2.07 x 11.3 = about 23g but you should be more exact than that.
Then 3.4E-22 x # Pb atoms = about 23 g
Solve for # Pb atoms.

so, is it equal 6.9*10^22 ?

To solve this problem, we need to use the concept of density and the formula to calculate the number of atoms. Here are the steps:

Step 1: Determine the mass of the lead cube.
Given that the volume of the lead cube is 2.07 cm^3, and the density of lead is 11.3 g/cm^3, we can calculate the mass using the formula:

Mass = Density * Volume

Plugging in the values:
Mass = 11.3 g/cm^3 * 2.07 cm^3

Step 2: Calculate the number of lead atoms.
To find the number of lead atoms, we need to convert the mass of the cube into the number of moles using the molar mass of lead, and then use Avogadro's number (6.022 × 10^23) to find the number of atoms.

The molar mass of lead is 207.2 g/mol.

Number of moles = mass (g) / molar mass (g/mol)

Step 3: Convert moles to atoms.
To convert moles to atoms, we multiply the number of moles by Avogadro's number (6.022 × 10^23).

Number of atoms = number of moles * Avogadro's number

Plugging in the values, substitute the mass in grams from step 1, and solve for the number of atoms.

Now you can follow these steps to calculate the number of lead atoms in the given cube of lead.