A neutral atom A has the electronic configuration: 1s2 2s2 2p6 3s2 3p6 4s1. It will gain or lose electron/s to form most probably an ion of valence:
Correct answer: D. +1
- A. -2
- B. -1
- C. +2
- D. +1
Explanation
The element with atomic number 19 is potassium (K) which is a group 1 metal. Hence it loses one electron to form the ion valence of K+1. Therefore the answer will be D.
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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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