Answer to Question #152898 in General Chemistry for Alex Katzburg

Question

If you were sitting near a gram of protactinium-234 and a gram of uranium-234, both solid materials, which would you consider more dangerous to you? Explain giving two reasons.

Answer 1

half life of radioactive decay, t_½ = ln2/λ

λ = decay constant

So, lower the half life High will be the decay constant.

Higher the decay constant (λ) higher will be the activity of the element and more dengerus the element is,

protactinium-234 = 234Pa91

Half life,t_½ = 1.17 min

uranium-234 = 234U92

Half life,t_½ = 245,000 year

As,

t_½ of protactinium-234< t_½ uranium-234

So,

λ of protactinium-234 > λ of uranium-234

So, protactinium-234 is more active than uranium-234 and consequently protactinium-234 is more dangerous than uranium-234.