Calcium-39 Undergoes Positron Decay

question 14

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 × 10 ⁴ kJ
• C)1.32 × 10 ⁶ kJ
• D)1.32 × 10 ⁹ kJ
• E)None of these choices are correct.

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Definitions:

Nucleic Acid

Complex organic substances that serve as the blueprint for genetic information in living organisms, primarily DNA andRNA, which encode the instructions for synthesizing proteins.

Carbohydrate

Compound containing carbon, hydrogen, and oxygen, in the approximate ratio of C:2H:O (e.g., sugars, starch, and cellulose).

Lipid

A group of naturally occurring molecules that include fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E, and K), monoglycerides, diglycerides, triglycerides, phospholipids, and others.

Protein

A large, complex organic compound composed of covalently linked amino acid subunits; contains carbon, hydrogen, oxygen, nitrogen, and sulfur.