Question

Electronic magic numbers of atoms are:
A. 2
B. 15
C. 10
D. 18
Choose the correct answer from the options given below:

• A. A, B and D only
• B. A, B and C only
• C. B, C and D only
• D. A, C and D only

Hint:

The electronic magic numbers for atoms are simply the atomic numbers of the noble gases found at the end of each row of the periodic table. Memorizing the first few (2, 10, 18, 36) is helpful for questions in atomic and chemical physics.

Answer 1

The Correct Option is D

Step 1: Concept of Electronic Magic Numbers:
In physics, magic numbers denote particle counts (protons, neutrons, or electrons) yielding complete shells and exceptional stability. Electronic magic numbers for atoms correspond to the atomic numbers (Z) of elements with filled electron shells, specifically the noble gases.
Step 2: Noble Gases and Magic Numbers:
Noble gases are chemically inert due to their stable, closed-shell electron configurations. Their atomic numbers are electronic magic numbers. Examples include:

Helium (He): Z = 2
Neon (Ne): Z = 10
Argon (Ar): Z = 18
Krypton (Kr): Z = 36
Xenon (Xe): Z = 54
Evaluating the options:

A. 2: Helium's atomic number, a magic number.
B. 15: Phosphorus's atomic number, not a magic number (no closed shell).
C. 10: Neon's atomic number, a magic number.
D. 18: Argon's atomic number, a magic number.

Step 3: Conclusion:
Options A, C, and D are correct. Select the option containing only A, C, and D.