How many uranium atoms are there in 6.2 g
of pure uranium? The mass of one uranium
atom is 4 × 10−26 kg.
6.2g * 1atom/4*10^-26kg * 1kg/1000g = 6.2/4 * 10^23 atoms
To find the number of uranium atoms in 6.2 g of pure uranium, we can use the concept of molar mass and Avogadro's number.
1. Convert the mass of one uranium atom from kg to grams:
4 × 10^(-26) kg = 4 × 10^(-26) × 1000 g = 4 × 10^(-23) g
2. Calculate the molar mass of uranium (U) using the periodic table:
The atomic mass of uranium (U) is approximately 238.03 g/mol.
3. Use the molar mass to find the number of moles of uranium in 6.2 g:
Number of moles = Mass of sample (g) / Molar mass (g/mol)
Number of moles = 6.2 g / 238.03 g/mol
4. Apply Avogadro's number to convert the number of moles to the number of atoms:
Avogadro's number (NA) is approximately 6.022 × 10^(23) atoms/mol.
Number of atoms = Number of moles × Avogadro's number
Now let's calculate it step by step:
Step 1:
Mass of one uranium atom = 4 × 10^(-23) g
Step 2:
Molar mass of uranium (U) = 238.03 g/mol
Step 3:
Number of moles = 6.2 g / 238.03 g/mol
Step 4:
Number of atoms = Number of moles × Avogadro's number
Number of atoms = (6.2 g / 238.03 g/mol) × (6.022 × 10^(23) atoms/mol)
Calculating the final result:
Number of atoms = (6.2 g / 238.03 g/mol) × (6.022 × 10^(23) atoms/mol) ≈ 1.569 × 10^(22) atoms
Therefore, there are approximately 1.569 × 10^(22) uranium atoms in 6.2 g of pure uranium.