Mneumonic for 3 types of Beta Decay?

[ilovemcat]

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I find myself frequently forgetting the results of Beta Decay:

Beta Capture (B- decay): Neutron -> Proton + Electron Particle
Beta Capture (B+ decay): Proton -> Neutron + Positron
Electron Capture: Electron -> Proton -> Neutron

Does anyone have a mnemonic to remember the different types of decay or at least an explanation that will help me remember the differences during the exam?

 

[Rabolisk]

Here's how I tend to remember it.
B- delay produces or releases an electron (add atomic number)
B+ delay produces or releases a positron (subtract atomic number)
Electron capture.. captures an electron (subtract atomic number)

Mass number always stays constant, unless it's an alpha decay.

 

[ilovemcat]

Here's how I tend to remember it.
B- delay produces or releases an electron (subtract atomic number)
B+ delay produces or releases a positron (add atomic number)
Electron capture.. captures an electron (subtract atomic number)

Mass number always stays constant, unless it's an alpha decay.

The first part of what you said is wrong.
Beta minus decay - Adds 1 to Atomic Number
Beta plus decay - Subtracts 1 to Atomic Number
EC - Subtracts 1 to Atomic Number

In all cases, mass number is the same (because with every proton/neutron gain there's a proton/neutron loss).

 

[MightyMoose]

Here's how I tend to remember it.
B- delay produces or releases an electron (subtract atomic number)
B+ delay produces or releases a positron (add atomic number)
Electron capture.. captures an electron (subtract atomic number)

Mass number always stays constant, unless it's an alpha decay.

That would be nice if it were correct...


B- adds a proton

B+ Subtracts a proton

You're talking about charges (in the +/-), so think opposites attract and it will be easy to remember - is + and + is -.

Then just think of alpha as a He nucleus.

 

[Rabolisk]

Ah!! it's late, my apologies.

 

[MightyMoose]

Ah!! it's late, my apologies.

I used to make the same mistake all the time myself. Now I just use the opposites attract mnemonic. It works like a charm.

 

[Don Draper]

The first part of what you said is wrong.
Beta minus decay - Adds 1 to Atomic Number
Beta plus decay - Subtracts 1 to Atomic Number
EC - Subtracts 1 to Atomic Number

In all cases, mass number is the same (because with every proton/neutron gain there's a proton/neutron loss).

hmmm.

Beta capture is like capturing an electron in the nucleus. So you would take away a proton.

Beta decay is like losing an electron in the nucleus. So you would add a proton.

This is one of the easier things to remember, it just makes sense. I know everyone uses different language (AAMC did), but I can't remember missing one of these questions throughout all my practice.

 

[ThrusH]

I don't really have any pneumonic to help you out with, but if you can remember where the +/- goes, then it should work out. I apologize for the poorly edited image, but hopefully this gets my point across. The image is courtesy of wikipedia with a little editing on my side.

Unless you capture anything, then the products side gets the e. You know that electrons have a negative charge, therefore, whenever you do electron capture, you are capturing an electron, i.e. reactants + e- --> products

If you are doing beta decay, put an e on the products side, and include the sign of whatever is in beta decay's name, i.e.
beta minus decay: reactant --> product + e-
beta plus decay: reactant --> product + e+.

Then just make sure that the numbers on top and bottom balance out. Since the Mass Number is just the number of protons and neutrons (beta decay turns protons to neutrons and neutrons to protons) you know that it won't change (make sure to put e's +/- charge on the Atomic number) and you should be set!

I hope this helps!