Which among the following has highest number of atoms?

Options

A. `5` g of ` CO_2`
B. `4` g of `CO`
C. `1` g of ` H_2`
D. `6` g of ` O_3`

Answer

To determine which among the given substances has the highest number of atoms, we will calculate the number of atoms for each substance based on the provided weights and their molecular formulas.

### Step-by-Step Solution:

1. **Calculate the number of moles for Carbon Dioxide (CO₂)**:
- Given weight = 5 grams
- Molar mass of CO₂ = 12 (C) + 16*2 (O) = 44 g/mol
- Number of moles = Given weight / Molar mass = 5 g / 44 g/mol = 0.1136 moles
- Number of atoms in CO₂ = Moles × Avogadro's number × 3 (since CO₂ has 3 atoms: 1 C + 2 O)
- Number of atoms = 0.1136 moles × 6.022 × 10²³ atoms/mole × 3 = 2.04 × 10²³ atoms

2. **Calculate the number of moles for Carbon Monoxide (CO)**:
- Given weight = 4 grams
- Molar mass of CO = 12 (C) + 16 (O) = 28 g/mol
- Number of moles = 4 g / 28 g/mol = 0.1429 moles
- Number of atoms in CO = Moles × Avogadro's number × 2 (since CO has 2 atoms: 1 C + 1 O)
- Number of atoms = 0.1429 moles × 6.022 × 10²³ atoms/mole × 2 = 1.72 × 10²³ atoms

3. **Calculate the number of moles for Hydrogen (H₂)**:
- Given weight = 1 gram
- Molar mass of H₂ = 1*2 = 2 g/mol
- Number of moles = 1 g / 2 g/mol = 0.5 moles
- Number of atoms in H₂ = Moles × Avogadro's number × 2 (since H₂ has 2 atoms)
- Number of atoms = 0.5 moles × 6.022 × 10²³ atoms/mole × 2 = 6.022 × 10²³ atoms

4. **Calculate the number of moles for Ozone (O₃)**:
- Given weight = 6 grams
- Molar mass of O₃ = 16*3 = 48 g/mol
- Number of moles = 6 g / 48 g/mol = 0.125 moles
- Number of atoms in O₃ = Moles × Avogadro's number × 3 (since O₃ has 3 atoms)
- Number of atoms = 0.125 moles × 6.022 × 10²³ atoms/mole × 3 = 2.26 × 10²³ atoms

5. **Comparison of the number of atoms**:
- CO₂: 2.04 × 10²³ atoms
- CO: 1.72 × 10²³ atoms
- H₂: 6.022 × 10²³ atoms
- O₃: 2.26 × 10²³ atoms

### Conclusion:
The substance with the highest number of atoms is **Hydrogen (H₂)** with **6.022 × 10²³ atoms**.