Question
mass number is what
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GPT-4o mini
The mass number is the total number of protons and neutrons in an atomic nucleus. It is usually denoted by the symbol \( A \). The mass number differs from the atomic number, which is the number of protons in the nucleus.
For example, if an element has:
- 6 protons and 6 neutrons (like Carbon-12), its mass number is \( 6 + 6 = 12 \).
- 6 protons and 7 neutrons (like Carbon-13), its mass number is \( 6 + 7 = 13 \).
Mass number is important for identifying isotopes of an element, which have the same number of protons but different numbers of neutrons. The mass number is often shown alongside the element's symbol, such as \( ^{12}\text{C} \) for Carbon-12 or \( ^{14}\text{C} \) for Carbon-14.
For example, if an element has:
- 6 protons and 6 neutrons (like Carbon-12), its mass number is \( 6 + 6 = 12 \).
- 6 protons and 7 neutrons (like Carbon-13), its mass number is \( 6 + 7 = 13 \).
Mass number is important for identifying isotopes of an element, which have the same number of protons but different numbers of neutrons. The mass number is often shown alongside the element's symbol, such as \( ^{12}\text{C} \) for Carbon-12 or \( ^{14}\text{C} \) for Carbon-14.