The Isotope Has a Half-Life of 5,715 Years

question 49

Multiple Choice

The isotope has a half-life of 5,715 years. After 2,000 years, a sample of the isotope is reduced to 2.1 grams. What was the initial size of the sample (in grams) ? How much will remain after 20,000 years (i.e., after another 18,000 years) ? Round your answers to four decimal places. ​

• A) 1.8735 g, 0.1656 g
• B) 4.2824 g, 0.3786 g
• C) 2.6765 g, 0.2366 g
• D) 3.7471 g, 0.3313 g
• E) 3.4794 g, 0.3076 g

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Definitions:

Disjuncts

Components in a logical expression that are combined with an OR operator, where the expression is true if at least one of the disjuncts is true.

Disjunction

An operation in logic that returns true when a minimum of one input is true.

Tautologies

Statements that are true under any possible valuation of their components in logic.

Biconditional

A logical statement that is true only if both the conditions it connects are either true or false.