What type of decay process is demonstrated in the following reaction 40 -19k to 0 -1e+40-20ca?

Answer is: beta decay.

Nuclear reaction: ⁴⁰K → ⁴⁰Ca + e⁻.

Beta decay is radioactive decay in which a beta ray and a neutrino are emitted from an atomic nucleus.  

There are two types of beta decay: beta minus and beta plus.  

In beta minus decay, neutron is converted to a proton and an electron and an electron antineutrino.

In this nuclear reaction, potassium (atomic number 19) changes to calcium (atomic number 20), atomic number Z is increased by one.

it would be d. henry moseley

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