The question cannot be definitively answered from the information given. It depends on the isotope what the decay modes are.
Brookhaven National Labs has an interactive chart of nuclides; you can click on a particular isotope and see the half-life and decay modes. I've put a link to it in the Related Links section.
Alpha particles, protons, neutrons, electrons, neutrinos, nucleus of lighter elements, electro magnetic radiation and so on.
Radioactive decay or radioactivity
radioactive decay
To become stable
Radioactivity
There are 3 different types of radioactive decay. alpha decay, beta decay and gamma decay. alpha decay is composed of a helium nuclei, beta decay emit either electrons or positrons, and finally gamma decay in which high energy "rays" of photons. A positron is a positively charged electron (antimatter twin of the electron). See the natural decay series of U-238 and others to see which daughters emit beta to alpha or gamma. there is also the neutrino. I cant say we really know that much about it but basically it helps satisfy the law of conservation.
Radioactive decay or radioactivity
Jerry Lewis Pietenpol has written: 'Atomic corrections to electric-quadrupole gamma decay by heavy nuclei' -- subject(s): Gamma decay, Heavy nuclei, Spectrum analysis
This process through which unstable nuclei emit radiation is called radioactive decay. It also is called nuclear decay, and it is a natural process in which an atom of an isotope decomposes into a new element.
No, the fusion process is the opposite of the radioactive decay process. Fusion is the merging together of nuclei to form a heavier nucleus whereas fission or radioactive decay is the splitting apart of a heavy nucleus into lighter daughter nuclei.
K capture, a special case of inverse beta decay that doesn't emit a positron (but it does emit an electron neutrino)
Because the structure of their nuclei is unstable: too many or too few neutrons, excess energy causing metastable state, etc. To get more stable they decay, emitting alpha, beta, and/or gamma radiation.
radioactive decay
To become stable
Some isotopes emit an electron on decay, others emit a positron (anti-electron).
Atomic nuclei that are unstable and decaying are said to be radioactive. Radioactive decay involves alpha, beta and gamma particle emissions.
radioactive
radiation