Calcium-39 Undergoes Positron Decay

question 34

Multiple Choice

Calcium-39 undergoes positron decay. Each positron carries 5.49 MeV of energy. How much energy will be emitted when 0.0025 mol of calcium-39 decays?

• A) 13.2 kJ
• B) 1.32 × 10⁴ kJ
• C) 1.32 × 10⁶ kJ
• D) 1.32 × 10⁹ kJ
• E) None of these choices are correct.

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Definitions:

Gastrulation

A phase early in embryonic development during which the single-layered blastula reorganizes into a multilayered structure, forming the embryonic germ layers.

Blastulation

An early stage in embryonic development that results in the formation of a blastula, a sphere of cells surrounding a fluid-filled cavity.

Gray Crescent

An area that appears on the surface of amphibian eggs following fertilization, indicating where the dorsal side of the embryo will develop.

Cleavage

The series of cell divisions of a fertilized egg that leads to the formation of the embryo.