Starting from radium, the radioactive disintegration process terminates when the following is obtained

Options

A. Radon
B. Lead
C. Uranium
D. Thorium

Explanation

To solve the question regarding the radioactive disintegration process starting from radium, we will follow these steps:

### Step 1: Identify the Starting Element
The starting element is radium (Ra), specifically radium-224 (Ra-224).

### Step 2: Understand the Disintegration Process
Radium undergoes radioactive decay, primarily through alpha decay. In alpha decay, the nucleus emits an alpha particle (which consists of 2 protons and 2 neutrons).

### Step 3: Determine the First Decay Product
When radium-224 emits an alpha particle, it transforms into radon-220 (Rn-220):
- **Ra-224 → Rn-220 + α**

### Step 4: Continue the Decay Process
Radon-220 is also radioactive and will undergo further decay. It emits another alpha particle to form polonium-216 (Po-216):
- **Rn-220 → Po-216 + α**

### Step 5: Identify the Next Decay Product
Polonium-216 will also undergo alpha decay to form lead-212 (Pb-212):
- **Po-216 → Pb-212 + α**

### Step 6: Determine Stability of the Final Product
Lead-212 is the final product of this decay chain. Among the elements produced (Ra, Rn, Po, and Pb), lead is the most stable isotope.

### Conclusion
The radioactive disintegration process starting from radium terminates when lead (Pb) is obtained. Therefore, the answer is lead.

### Final Answer
**Lead (Pb)** is the element obtained when the radioactive disintegration process starting from radium terminates.

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