${ } ^ { 14 } \mathrm { C }$

question 29

Multiple Choice

${ } ^ { 14 } \mathrm { C }$ has a half life of 5730 years. How old is a piece of charcoal which has lost 90% of its ${ } ^ { 14 } \mathrm { C }$ ?

• A) 20,000 years
• B) 11,109 years
• C) 9100 years
• D) 19,109 years
• E) none of these