The numbers of protons, electrons and neutrons in a molecule of heavy water are respectively

Options

A. 10,10,10
B. 8,10,11
C. 10,11,10
D. 11,10,10

Answer

To find the number of protons, electrons, and neutrons in a molecule of heavy water (D2O), we can follow these steps:

### Step 1: Identify the components of heavy water
Heavy water consists of two deuterium (D) atoms and one oxygen (O) atom.

### Step 2: Determine the number of protons
- **Deuterium (D)**:
- Atomic number = 1 (indicating 1 proton)
- Since there are 2 deuterium atoms, the total number of protons from deuterium = 2 × 1 = 2.

- **Oxygen (O)**:
- Atomic number = 8 (indicating 8 protons)

- **Total number of protons** = Protons from deuterium + Protons from oxygen = 2 + 8 = 10.

### Step 3: Determine the number of electrons
- Heavy water (D2O) is a neutral molecule, meaning the number of electrons is equal to the number of protons.
- Therefore, the number of electrons = Total number of protons = 10.

### Step 4: Determine the number of neutrons
- **Molar mass of deuterium** = 2 (since deuterium has 1 proton and 1 neutron).
- **Molar mass of oxygen** = 16 (since oxygen has 8 protons and 8 neutrons).

- **Total molar mass of D2O** = (2 × 2) + 16 = 4 + 16 = 20.

- **Number of neutrons** can be calculated using the formula:
\[ \text{Number of neutrons} = \text{Molar mass} - \text{Number of protons} \]
\[ \text{Number of neutrons} = 20 - 10 = 10. \]

### Conclusion
- The numbers of protons, electrons, and neutrons in a molecule of heavy water (D2O) are respectively: **10 protons, 10 electrons, and 10 neutrons**.