Which of the following is different in Na+ (Z=11), Mg+2 (Z=12) and AI+3 (Z=13)?
Correct answer: D. Number of protons
- A. Number of shells
- B. Number of electrons
- C. Electronic configuration
- D. Number of protons
Explanation
The atomic number of Na is 11, so it has 11 electrons and 11 protons . But Na+ has lost 1 electron, so Na+ has 10 electrons and 11 protons. The atomic number of Mg is 12, so it has 12 protons and 12 electrons. But Mg2+ has lost 2 electrons, so Mg2+ has 10 electrons and 12 protons. The atomic number of Al is 13, so it has 13 protons and 13 electrons. But Al3+ has lost 3 electrons, so Al3+ has 10 electrons and 13 protons. So, Na+, Mg2+, Al3+ all have different number of protons. Hence, option D is correct.
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About s-Block and p-Block Elements
The s and p blocks are studied through their valence-shell configurations, periodic trends and characteristic chemical properties. Work covers the reactions of Group I and Group II elements, the behaviour of Group IV elements, and how atomic size, ionization energy, electronegativity and metallic character change across periods and down groups.
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