The mass number of a nucleus is [2003]a)sometimes less than and someti...
In case of hydrogen atom, Mass number = atomic number
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The mass number of a nucleus is [2003]a)sometimes less than and someti...
Understanding Mass Number and Atomic Number
The mass number and atomic number are fundamental concepts in nuclear physics and chemistry. They help us understand the structure of an atom.
Definitions:
- Mass Number (A): The total number of protons and neutrons in a nucleus.
- Atomic Number (Z): The number of protons in the nucleus, which determines the element's identity.
Relationship Between Mass Number and Atomic Number:
- The mass number can be equal to, greater than, or less than the atomic number, depending on the element.
Key Points to Consider:
- Equal Case: For hydrogen-1, which has 1 proton and 0 neutrons, the mass number (1) is equal to the atomic number (1).
- Greater Case: Most elements have more neutrons than protons. For example, carbon-12 has 6 protons and 6 neutrons, giving a mass number of 12, which is more than its atomic number (6).
- Less Case: There are no common stable isotopes where the mass number is less than the atomic number, but in hypothetical scenarios or certain exotic isotopes, this might theoretically occur.
Conclusion:
Thus, the correct answer is option 'D': the mass number is sometimes equal to its atomic number. This occurs in specific isotopes, illustrating the nuanced relationship between these two atomic properties. Understanding this relationship is crucial for grasping the behavior of different elements in the periodic table.