Potassium-40 Decays to Argon-40 with a Half-Life of 1

question 24

Multiple Choice

Potassium-40 decays to argon-40 with a half-life of 1.27 × 10⁹ yr. The age of a mineral sample that has a mass ratio of ⁴⁰Ar to ⁴⁰K of 0.412 is ________ y.

• A) 1.62 × 10⁹
• B) 5.23 × 10⁸
• C) 7.55 × 10⁸
• D) 2.26 × 10⁹
• E) 6.32 × 10⁸

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Definitions:

Deformed

Referring to rocks or earth materials that have been changed in shape or dimension under stress, such as during tectonic activity.

Flattened

Describes objects that have been pressed into a thinner shape or planar surface, often as a result of external pressure.

Low Pressure

A condition in the atmosphere where the air pressure is lower than surrounding areas, often leading to cloudy weather and precipitation.

High Temperature

A condition or state of matter characterized by a heat level that is significantly above the normal or expected temperature range.