Iodine-131 is a radioactive isotope with a half-life of 8 days. how many grams of a 64 gram sample of iodine-131 will remain after 24 days?

a) 56g
b) 48g
c) 32g
d) 8g

D) 8g

Explanation:

Given data:

Half life of I-131 =  8 days

Total amount of sample = 64 g

Amount remain after 24 days = ?

Solution:

Number of half lives = T elapsed / Half life

Number of half lives = 24 days / 8 days

Number of half lives = 3

At time zero = 64 g

At 1st half life = 64 g/ 2= 32 g

At second half life = 32 g /2 = 16 g

At third half life = 16 g/ 2 = 8 g

water and alcohols have similar properties because water molecules contain hydroxyl groups that can form hydrogen bonds with other water molecules and with alcohol molecules, and likewise alcohol molecules can form hydrogen bonds with other alcohol molecules as well as with water.