What type of radiation is emitted when K-38 decays into Ca-38?

Answer 1

K-38 is element 19. It has 19 protons. So it has 38 - 19 = 19 neutrons.
Ca-38 is element 20. It has 20 protons. So it has 38 - 20 = 18 neutrons.

Ca-38 has gained a proton and lost a neutron. So a neutron must have decayed into a proton.

Answer 2

Thank you !

Answer 3

Your Welcome xD!