Alab technician had a sample of radioactive americium. he knew it was one of the isotopes listed in the table below but did not know which one. the sample originally contained 0.008 g of the isotope, but 120 minutes later it contained 0.002 g. a. how many half-lives have passed? b. what is the half-life of the sample? c. which isotope did he have?

a. 2

b. 1 hour

c. Am-237

Explanation:

Half life is the time taken by a reactant to reduce to its original concentration. It is designated by the symbol .

Formula used :

where,

a = amount of reactant left after n-half lives = 0.002

= Initial amount of the reactant = 0.008 g

n = number of half lives  = ?

Putting values in above equation, we get:

Thus two half lives have passed.

2. If two half lives have passed in 120 minutes

one half life will be passed in = or 1 hour

3. As half life is characteristic of a particular isotope.

Given : the half life of isotope Am-237 is 1 hour or 60 minutes. thus the isotope was Am-237.

? you expect us to answer this? ? this is your schoolwork, i don't think we can with this, i think it would considering being

the ozone layer acts as a filter for the shorter wavelength and highly hazardous ultraviolet radiation (uvr) from the sun, protecting life on earth from its potentially harmful effects. when the sky is clear, there is an inverse relationship between stratospheric ozone and solar uvr measured at the earth's surface.