Sum of protons and neutrons in an atom gives off _________ ?
Correct answer: D. Both A and B
- A. Nucleon numbera
- B. Mass number
- C. Atomic number
- D. Both A and B
Explanation
The sum of protons and neutrons is called the mass number, and it is also called the nucleon number because protons and neutrons are nucleons. Atomic number counts only protons. Students may choose atomic number because it is another important nuclear quantity, but it does not include neutrons.
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About Electronic Configuration
Electronic configuration describes how electrons occupy shells, subshells and orbitals around an atom. Questions use the Aufbau principle, Pauli exclusion principle and Hund's rule to write configurations, identify valence electrons, form ions and explain periodic trends, including common exceptions such as chromium and copper.
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