Oxygen-15, used in imaging brain function and blood flow, has a half-life of 2 min. How many half-lives have occurred in the 10 min it takes to prepare the sample?

Number of half lives = 5

Explanation:

Given data:

Half life of oxygen = 2 min

Half lives occured in 10 min = ?

Solution:

Formula;

Number of half lives = Time elapsed / half life

by putting values,

Number of half lives = 10 min / 2 min

Number of half lives = 5

indium, and thallium have three electrons i think