The fraction of half-life will remain in 139 years will be 1/16.
What is half life?
the time required for half of something to undergo a process, such as, the time required for half of the atoms of a radioactive substance to become disintegrated.
Let staring fraction = x
Half-life = 88 years ; this is the time taken for an element to decrease to half of its original size.
Hence,
After 80 years - - - > x/2
After 100 years - - - - > x/2 ÷ 2 = x/2 * 1/2 = x /4
After 120 years - - - - > x/4 ÷ 2 = x/4 * 1/2 = x/8
After 140 years - - - - -> x/8 ÷ 2 = x/8 * 1/2 = x / 16
Therefore, the fraction of half-life after 139 years = 1/16.
To know more about half-life, refer: https://brainly.com/question/14938666
#SPJ4