Radioactive Decay

[johnnycarbona]

Cancers of the bone can be treated with radium-233. After this isotope undergoes two rounds of alpha decay and one round of beta decay, the remaining substance will possess chemical properties most similar to:

A. Na
B. Mg
C. O
D. Cl

Answer is C. Why?

 

[Sephirakra]

Cancers of the bone can be treated with radium-233. After this isotope undergoes two rounds of alpha decay and one round of beta decay, the remaining substance will possess chemical properties most similar to:

A. Na
B. Mg
C. O
D. Cl

Answer is C. Why?

What effect do alpha and beta decay have on an atom?

 

[deleted987519]

Review effects of a- B- decay on atom, draw out balanced rxns for what the question lists, see what your final element is and which column it’s in on periodic table

 

[johnnycarbona]

Right so starting with radium 233, 88 protons - then 2x alpha decay = lose 4 protons, 4 neutrons - so from 88 to 84 protons = Polonium, mass number 225. Then one round of beta decay - so gains one proton = 85 protons. Astatine 225. That is in the same column as chlorine, not oxygen. ?

 

[deleted872555]

Right so starting with radium 233, 88 protons - then 2x alpha decay = lose 4 protons, 4 neutrons - so from 88 to 84 protons = Polonium, mass number 225. Then one round of beta decay - so gains one proton = 85 protons. Astatine 225. That is in the same column as chlorine, not oxygen. ?

yeah i got Astatine as well, which is in the same period as the halogens.

i’m intrigued..

 

[Sephirakra]

Right so starting with radium 233, 88 protons - then 2x alpha decay = lose 4 protons, 4 neutrons - so from 88 to 84 protons = Polonium, mass number 225. Then one round of beta decay - so gains one proton = 85 protons. Astatine 225. That is in the same column as chlorine, not oxygen. ?

Where did you find this question?

 

[johnnycarbona]

ExamKrackers. There have been several errors so far, this could be one - didn't want to assume that though.