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Physics · Class 12

Alpha beta gamma changes

Nuclei

Alpha is a helium nucleus, beta minus an electron from a nuclear conversion, and gamma a photon. Their charge and mass differ, producing different deflection and penetration behavior. Only gamma emission leaves both A and Z unchanged.

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Alpha beta gamma changes

ஆல்பா ஹீலியம் அணுக்கரு; பீட்டா மைனஸ் எலக்ட்ரான்; காமா ஃபோட்டான். காமா வெளியீட்டில் A மற்றும் Z மாறாது.

Key notes, relationships and model limits

Key relationship

α: A→A−4,Z→Z−2; β−: A fixed,Z→Z+1; γ: A,Z fixed.

Remember

Alpha is a helium nucleus, beta minus an electron from a nuclear conversion, and gamma a photon. Their charge and mass differ, producing different deflection and penetration behavior. Only gamma emission leaves both A and Z unchanged.

Common trap

A beta electron is created in the nuclear process, not removed from an atomic orbit.

Model limits

Beta minus only. Penetration is an explicit illustrative solid-range model, not a material-specific shielding calculation: α/β finite ranges, γ exponential attenuation. Ionization ordering is qualitative.

What you will learn

Track nuclear notation and compare radiation properties.

Try the experiment

Try both scenarios, change one control, and predict the result before checking the graph and readouts.

Think of it this way

Change one input while keeping the others fixed, as you would in a controlled experiment.

Worked example

An alpha daughter of Z84,A210 has Z82,A206.

Why this matters

The model connects alpha beta gamma changes with an observable reading. Check the equation and assumptions before applying it.

Before you start

SI units · algebra · graph reading

Check your understanding

In beta-minus decay, the daughter mass number is?

Read the explanation

A neutron converts to a proton, retaining the nucleon count.

Course connection: Class XII Chapter 13. Consult the roadmap for CBSE, NEET, JEE Main and Advanced scope.