Question

17.The half-life of the radioactive isotope silver-104 is 30 minutes. After how many minutes will about 20 grams of a 40-gram sample of the silver-104 isotope remain?Select one:a. 0b. 60c. 90d. 30

Answer 1

half-life means the time it takes for half the amount of a substance to decay.

for silver-104 this is 30 min. so after 30 minutes the amount of silver will have halved.

if we have 40 grams. after 30 minutes we will have 20 grams and after another 30 minutes we will have 10 grams and so forth.

so it would take roughly 30 minutes to have 20 grams left

ANSWER

option d