A Radioactive Substance Is Observed to Disintegrate at a Rate $\frac { 9 } { 10 }$

Multiple Choice

A radioactive substance is observed to disintegrate at a rate such that $\frac { 9 } { 10 }$ of the original amount remains after one year. What is the half-life of the substance?

A) 0.301 yr
B) 0.588 yr
C) 0.556 yr
D) 6.579 yr