Give 4 uses of isotopes.

Answer

### Step-by-Step Text Solution

1. **Definition of Isotopes**:
Isotopes are atoms of the same element that have the same atomic number but different mass numbers. This means they have the same number of protons but a different number of neutrons.

2. **Use of Uranium-235**:
One of the major uses of isotopes is in nuclear reactors. Uranium-235 is used as a fuel in nuclear power plants. During the process of nuclear fission, Uranium-235 undergoes a reaction that releases a large amount of energy, which is harnessed for electricity generation.

3. **Use of Iodine-131**:
Iodine-131 is another important isotope that is used in the medical field, specifically in the treatment of goitre. Goitre is a condition characterized by the enlargement of the thyroid gland, often due to iodine deficiency. Iodine-131 is administered to help reduce the size of the thyroid gland.

4. **Use of Cobalt-60**:
Cobalt-60 is used in cancer treatment, particularly in radiation therapy. It emits gamma rays that can kill cancerous cells, making it effective for treating tumors and other malignancies.

5. **Use of Carbon-14**:
Carbon-14 is widely used in archaeology and geology for dating ancient organic materials. This isotope helps determine the age of fossils, bones, and other archaeological finds through a process known as radiocarbon dating.

### Summary of Uses:
- **Uranium-235**: Fuel in nuclear reactors.
- **Iodine-131**: Treatment of goitre.
- **Cobalt-60**: Cancer treatment.
- **Carbon-14**: Dating of fossils and ancient organic materials.

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