Estimate the number of atoms in 2.429 g of iron using the mass of an atomic mass unit (1.661 x 10 ^ -27). The atomic mass of Fe is 55.85 u.

To estimate the number of atoms in a given mass of iron, we can use the following steps:

Step 1: Calculate the molar mass of iron (Fe):
The molar mass of Fe is given as 55.85 u (atomic mass units). This means that 1 mole of Fe atoms has a mass of 55.85 grams.

Step 2: Convert the given mass of iron to moles:
We are given the mass of iron as 2.429 grams. To convert this to moles, we use the formula:
moles = given mass / molar mass

moles of Fe = 2.429 g / 55.85 g/mol ≈ 0.0435 moles

Step 3: Determine the number of atoms in the given moles of Fe:
Avogadro's number tells us that 1 mole of any substance contains 6.022 x 10^23 particles (atoms, molecules, etc.). Therefore, we can multiply the number of moles by Avogadro's number to find the number of atoms:

number of atoms = moles of Fe × Avogadro's number

number of atoms = 0.0435 moles × 6.022 x 10^23 atoms/mol

number of atoms ≈ 2.618 x 10^22 atoms

So, there are approximately 2.618 x 10^22 atoms in 2.429 grams of iron.