A Radioactive Material Initially Is Observed to Have an Activity

question 72

Multiple Choice

A radioactive material initially is observed to have an activity of 1 000 decays/sec.If three hours later it is observed to have an activity of 125 decays/sec,what is its half-life?

• A)1/2 hour
• B)1 hour
• C)3 hours
• D)8 hours

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Definitions:

Detect Causes

The process of identifying factors or conditions that lead to the occurrence of a particular event or phenomenon.

Stereotypes

Widely held but fixed and oversimplified images or ideas of a particular type of person or thing, which often do not reflect reality.

Self-Fulfilling Prophecies

Expectations about a situation or person that lead to behaviors which cause the expectation to come true.

Cognitive Dissonance

A psychological concept describing the discomfort felt when holding conflicting cognition, beliefs, or values, prompting individuals to seek consistency.