Chemistry

Question Analysis
This question involves multi-step isotope characterization (element identity, naming, nuclear notation) from subatomic particle counts.
The main focus is on integrating atomic number, mass number, element symbols, and notation rules.

Key Concept Explanation
Protons = atomic number = 20 → element = calcium (Ca, periodic table).
Mass number = protons + neutrons = 20 + 22 = 42 → isotope name = calcium-42.
Nuclear notation: subscript = atomic number (20), superscript = mass number (42), symbol = Ca.

Step-by-Step Solution
1. Identify element: 20 protons = calcium (Ca) (check periodic table for atomic number 20).
2. Calculate mass number: 20 + 22 = 42 → isotope name = calcium-42.
3. Assign nuclear notation parts: subscript = 20 (atomic number), superscript = 42 (mass number).
4. Fill in blanks with Ca, calcium-42, 20, 42.

Common Mistakes
Misidentifying the element (e.g., K for potassium, atomic number 19, instead of Ca for 20).
Miscalculating mass number (e.g., 20 - 22 = -2 or 20 + 20 = 40, ignoring neutrons).
Swapping subscript/superscript in nuclear notation (e.g.,

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