Cobalt-60, with a half-life of 5.0 days, is used in cancer radiation treatments. A hospital purchases a 30.0g supply of it and stores it on a shelf in a closet. The next time a hospital worker grabs the bottle, though, they find that it only contains 3.75 g remaining! Assuming the bottle had never been opened, how long was the bottle sitting on the shelf before the worked grabbed it?

Bottle is sitting on the shelf for 15 days.

Explanation:

Given data:

Co-60 half life = 5 days

Total amount = 30.0 g

Amount left = 3.75 g

Time taken = ?

Solution:

AT time zero = 30 g

AT first half life= 30g /2 = 15 g

At 2nd half life = 15 g/ 2 = 7.5 g

At 3rd half life = 7.5 g/2 = 3.75 g

Now we will calculate the sitting time of bottle.

Half life = Time taken / number of half lives

3× 5 days = time taken

Time taken = 15 days

Bottle is sitting on the shelf for 15 days.

they are both synthetic elements

explanation:

d

2b2t

explanation:

2b2t