A Certain Radioactive Isotope Placed near a Geiger Counter Registers

question 67

Multiple Choice

A certain radioactive isotope placed near a Geiger counter registers 160 counts per minute. Eight hours later, the counter registers 10 counts per minute. What is the half-life of the isotope?

• A)8 hours
• B)6 hours
• C)4 hours
• D)2 hours
• E)none of the above

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Definitions:

Desegregated Regiments

Military units in which members of different races are integrated, as opposed to segregated units which were racially divided.

Platt Amendment

An amendment to a U.S. Army appropriations bill in 1901, establishing the terms under which the United States would end its military occupation of Cuba and "guarantee" Cuban independence.

Military Occupation

The control and possession of a territory by a foreign military force.

Insular Cases

A series of early 20th-century Supreme Court decisions that determined the applicability of the U.S. Constitution to territories acquired by the United States, notably ruling that full constitutional rights do not automatically extend to all areas under American control.