Isotopes of an element have

Options

A. the same physical properties
B. different chemical properties
C. different number of neutrons
D. different atomic numbers.

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 in their nuclei.

2. **Example of Isotopes**: Taking hydrogen as an example, it has three isotopes: protium, deuterium, and tritium.
- Protium has an atomic number of 1 and a mass number of 1 (1 proton, 0 neutrons).
- Deuterium has an atomic number of 1 and a mass number of 2 (1 proton, 1 neutron).
- Tritium has an atomic number of 1 and a mass number of 3 (1 proton, 2 neutrons).

3. **Understanding Atomic Number and Mass Number**:
- The atomic number (Z) is the number of protons in the nucleus and is the same for all isotopes of an element.
- The mass number (A) is the sum of protons and neutrons in the nucleus.

4. **Calculating Neutrons**: To find the number of neutrons in an isotope, you can use the formula:
\[ \text{Number of Neutrons} = \text{Mass Number} - \text{Atomic Number} \]
- For protium: \( 1 - 1 = 0 \) neutrons.
- For deuterium: \( 2 - 1 = 1 \) neutron.
- For tritium: \( 3 - 1 = 2 \) neutrons.

5. **Conclusion**: Therefore, isotopes of an element have the same atomic number (same number of protons) but different mass numbers (different number of neutrons).

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