The number of neutrons in `1*8` g of water will approximately be

Options

A. `4*216xx10^(23)`
B. `8*432xx10^(23)`
C. `4*816xx10^(23)`
D. `4*216xx10^(24)`

Explanation

To find the number of neutrons in 1.8 g of water, we can follow these steps:

### Step 1: Determine the composition of water (H₂O)
Water consists of 2 hydrogen (H) atoms and 1 oxygen (O) atom.

### Step 2: Find the atomic mass and neutrons for each atom
- **Hydrogen (H)**:
- Atomic number = 1 (1 proton)
- Mass number = 1 (therefore, 0 neutrons)

- **Oxygen (O)**:
- Atomic number = 8 (8 protons)
- Mass number = 16 (therefore, 16 - 8 = 8 neutrons)

### Step 3: Calculate the total number of neutrons in one molecule of water (H₂O)
- Total neutrons in H₂O = Neutrons in H + Neutrons in O
- Total neutrons = 0 (from H) + 8 (from O) = 8 neutrons

### Step 4: Calculate the number of moles of water in 1.8 g
- Molar mass of water (H₂O) = 18 g/mol
- Number of moles = Given mass / Molar mass
- Number of moles = 1.8 g / 18 g/mol = 0.1 moles

### Step 5: Calculate the number of molecules in 0.1 moles of water
- Use Avogadro's number (6.022 x 10²³ molecules/mol)
- Number of molecules = Number of moles × Avogadro's number
- Number of molecules = 0.1 moles × 6.022 x 10²³ molecules/mol = 6.022 x 10²² molecules

### Step 6: Calculate the total number of neutrons in 1.8 g of water
- Total neutrons = Number of molecules × Neutrons per molecule
- Total neutrons = 6.022 x 10²² molecules × 8 neutrons/molecule = 4.8176 x 10²³ neutrons

### Final Answer:
The number of neutrons in 1.8 g of water is approximately **4.82 x 10²³ neutrons**.

---