`H_(2)O_(2)` and heavy water was discovered by respectively :

Options

A. Thernard, Urey
B. Urey, Rutherford
C. Aston, Urey
D. Aston, Chadwick

Answer

To solve the question regarding the discovery of H₂O₂ (hydrogen peroxide) and heavy water (D₂O), we can break it down into the following steps:

### Step 1: Identify the compound H₂O₂
- H₂O₂ is known as hydrogen peroxide. It is a chemical compound that consists of two hydrogen atoms and two oxygen atoms.

### Step 2: Research the discovery of H₂O₂
- Hydrogen peroxide was discovered by the scientist Louis Jacques Thénard in the year 1818. This is an important historical fact regarding the compound.

### Step 3: Identify the compound heavy water
- Heavy water is chemically represented as D₂O, where D stands for deuterium, an isotope of hydrogen. In heavy water, the hydrogen atoms in regular water (H₂O) are replaced with deuterium atoms.

### Step 4: Research the discovery of heavy water
- Heavy water was discovered by Harold Urey in 1932. Urey's work on isotopes led to the identification of deuterium and consequently heavy water.

### Step 5: Compile the information
- Now that we have the information:
- H₂O₂ was discovered by Thénard in 1818.
- Heavy water (D₂O) was discovered by Urey in 1932.

### Step 6: Choose the correct option
- Based on the discoveries, the correct answer to the question is that H₂O₂ and heavy water were discovered by Thénard and Urey, respectively.

### Final Answer:
The correct option is **Thénard and Urey**.

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