Question

what is formed when thorium 232 undergoes alpha decay?

Answer 1

Atomic number of Thorium (Th) = 90

So,

number of proton in Thorium (Th) = 90

Atomic mass number of Thorium (Th) =232

So,

Total number of (proton + neutron) of Thorium (Th) = 232

i.e. symbol of Thorium (Th) atom = ²³²Th₉₀

In Alpha (α) particle

the number of proton = 2

So, the number of neutron = 2

i.e symbol of Alpha (α) particle = ⁴α₂

When one alpha (α) particle decays from ²³²Th₉₀ atomic number reduced by 2 and mass number reduced by 4

i.e following reaction will occur

²³²Th₉₀ ––·> ²²⁸Ra₈₈ + ⁴α₂

Hence,

When alpha (α) particle decays from Thorium Radium, ²²⁸Ra₈₈ will produce