The splitting of a heavy nuclei with neutron into two smaller nuclei and large amount of energy is known as `…………………..` .

Answer

To solve the question, we need to identify the process described in the statement. Let's break it down step by step:

### Step 1: Understand the Process
The question describes a phenomenon where a heavy nucleus splits into smaller nuclei upon being bombarded with neutrons. This process also releases a large amount of energy.

### Step 2: Identify the Key Terms
- **Heavy Nucleus**: Refers to a nucleus with a large atomic mass, such as uranium or plutonium.
- **Neutron Bombardment**: This is when neutrons collide with the nucleus, causing it to become unstable.
- **Splitting into Smaller Nuclei**: This indicates that the heavy nucleus is breaking apart into two or more lighter nuclei.

### Step 3: Recognize the Energy Release
The process mentioned is known for releasing a significant amount of energy, which is a characteristic of nuclear reactions.

### Step 4: Recall the Terminology
The splitting of a heavy nucleus into smaller nuclei due to neutron bombardment is a well-known nuclear reaction. The term that describes this process is "nuclear fission."

### Final Answer
The splitting of a heavy nucleus with neutron into two smaller nuclei and a large amount of energy is known as **nuclear fission**.

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