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Atomic Mass Number Formula:
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The atomic mass number (A) represents the total number of protons and neutrons in an atom's nucleus. It is a fundamental property that helps identify isotopes of elements and determines the atomic mass of an atom.
The calculator uses the atomic mass number formula:
Where:
Explanation: The mass number is simply the sum of protons and neutrons in the atomic nucleus. Protons determine the element, while neutrons contribute to the mass and stability.
Details: Calculating mass number is essential for understanding atomic structure, identifying isotopes, predicting nuclear stability, and studying nuclear reactions and radioactive decay.
Tips: Enter the number of protons and neutrons as whole numbers. Both values must be non-negative integers. The calculator will instantly compute the atomic mass number.
Q1: What is the difference between mass number and atomic mass?
A: Mass number is the total count of protons and neutrons (a whole number), while atomic mass is the weighted average mass of all isotopes (a decimal value).
Q2: Can mass number be fractional?
A: No, mass number is always a whole number since it represents a count of particles. Atomic mass can be fractional due to isotope averaging.
Q3: How does mass number relate to isotopes?
A: Isotopes of an element have the same number of protons but different numbers of neutrons, resulting in different mass numbers.
Q4: Why is mass number important in nuclear chemistry?
A: Mass number helps identify nuclides, predict nuclear stability, and balance nuclear equations for radioactive decay and nuclear reactions.
Q5: Can two different elements have the same mass number?
A: Yes, different elements can have the same mass number (isobars), but they will have different atomic numbers and chemical properties.