mcatprep

Radioactivity

Types of Radioactive Decay

Mode of decay	Effect on parent nucleus	Example
a emission	Mass number decreases by 4 Atomic number decreases by 2	_{86Rn²¹⁰ ®₈₄Po²⁰⁶ + ₂He⁴}
b emission	Neutron turns into a proton Atomic number increases by 1 Mass number remains the same	_{6C¹⁴ ®₇N¹⁴ + _-1e⁰}
Electron capture	Proton turns into a neutron Atomic number decreases by 1 Mass number remains the same	_{53I¹²⁵ + _-1e⁰ ®₅₂Te¹²⁵ + X-ray photon (The captured electron decelerates and its kinetic energy is converted into electromagnetic energy)}
Positron emission	Proton turns into a neutron Atomic number decreases by 1 Mass number remains the same	_{5B⁸ ®₄Be⁸ + ₊₁e⁰}
g emission	None except nucleus becomes less excited	_{43Tc^99M ®₄₃Tc⁹⁹ + g (The "M" stands for metastable)}
Spontaneous fission	Becomes much smaller	_{98Cf²⁵² ®₅₄Xe¹⁴⁰ + ₄₄Ru¹⁰⁸ + 4 ₀n¹}