If Originally There Were X Atoms of Radioactive Isotope Present

question 149

Multiple Choice

If originally there were X atoms of radioactive isotope present and now there are only X/16 atoms, how many half-lives have elapsed?

• A) 4
• B) 1
• C) 2
• D) 3

---

Definitions:

Asymmetric Carbons

Carbon atoms bonded to four different groups, resulting in chirality or the existence of nonsuperimposable mirror images.

Chiral

Describes a molecule that cannot be superimposed on its mirror image, often resulting in different biological activities for each form.

Achiral

Lacking chirality; not having a non-superimposable mirror image.

Asymmetric Carbon

An asymmetric carbon, also known as a chiral carbon, is a carbon atom that is attached to four different groups, making its mirror image not superimposable on itself.