MCQ Collection
MDCAT 2026 MCQs
Practice MDCAT 2026 questions with answers and explanations.
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Correct Answer: D. Na
Explanation:
Forming Na+ removes the outer 3s electron.
The cation is smaller than the neutral atom.
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Correct Answer: B. Linear
Explanation:
Two electron groups arrange 180 degrees apart.
This minimizes repulsion.
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Correct Answer: A. A fatty acid with no carbon-carbon double bonds
Explanation:
Saturated fatty acids are fully saturated with hydrogen.
They are often solid at room temperature.
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Correct Answer: A. No two electrons in an atom have the same four quantum numbers
Explanation:
The principle limits each orbital to two opposite-spin electrons.
It is fundamental to electron configuration.
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Correct Answer: B. A fatty acid with no carbon-carbon double bonds
Explanation:
Saturated fatty acids are fully saturated with hydrogen.
They are often solid at room temperature.
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Correct Answer: B. Its lowest-energy electron arrangement
Explanation:
The ground state is the most stable configuration.
Energy absorption can promote electrons to excited states.
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Correct Answer: C. A fatty acid with one or more carbon-carbon double bonds
Explanation:
Double bonds introduce bends into fatty-acid chains.
They often increase membrane fluidity.
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Correct Answer: C. A state with one or more electrons at higher energy than the ground state
Explanation:
Excited atoms can return to lower levels by emitting energy.
Atomic spectra arise from these transitions.
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Correct Answer: D. A fatty acid with one or more carbon-carbon double bonds
Explanation:
Double bonds introduce bends into fatty-acid chains.
They often increase membrane fluidity.
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Correct Answer: D. Energy required to remove an electron from a gaseous atom or ion
Explanation:
First ionization energy removes the first electron from a neutral gaseous atom.
Successive ionization energies remove additional electrons.
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Correct Answer: A. A fatty acid with one or more carbon-carbon double bonds
Explanation:
Double bonds introduce bends into fatty-acid chains.
They often increase membrane fluidity.
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Correct Answer: A. Energy change when a gaseous atom gains an electron
Explanation:
Electron affinity reflects attraction for an added electron.
Its sign and magnitude vary across the periodic table.
