Using general tendencies and the chart given in the introduction, predict the most likely mode of decay of each of the following radioactive isotopes.

Drag the appropriate items to their respective bins.

Note: Based on the valley of stability, the following processes generally tend to produce more stable neutron-to-proton (n/p) ratios:
Nuclei with Z≥84 tend to undergo α emission.
Nuclei with high n/p ratios undergo β ( 0−1e) emission.
Heavy nuclei with low n/p ratios are more likely to undergo electron ( 0−1e) capture.
Light nuclei with low n/p ratios are more likely to undergo positron (01e) emission.
The classification "high" or "low" n/p ratio can be determined by finding the coordinates on the graph that correspond to the number of protons (x or horizontal value) and neutrons (y or vertical value) in a given isotope. Then, observe whether this set of coordinates is above, within, or below the stability valley.

My Effort to Solve it myself:
K-47, Hg-190, Th-232, Na-20, I-137

# of. p n order of greatest atomic mass
K: 19 28 4
Hg: 80 110 2
Th: 90 142 1
Na: 11 9 5
I: 53 84 3

K-47 undergoes beta decay

Hg-190 undergoes electron capture or alpha decay

Th-232 undergoes alpha decay

Na-20 undergoes positron emission

I-137 undergoes beta decay

Explanation:

Stability of a nucleus is decided by the neutron /proton (n/p) ratio. For lower elements of atomic number 1-20, n/p=1. Elements with higher atomic numbers tend to have a slight excess of neutrons to reduce the repulsive forces between the protons.

Beta emission decreases the n/p ratio, positron emission increases the n/p ratio, electron capture increases the n/p ratio and alpha decay increases the n/p ratio.

Note that a nucleus may undergo several decay processes before stable nucleus (nuclei) is/are formed.

definition

                    entropy is a measure of the randomness or the extent of disorder of a chemical process.

                      enthalpy is a measure of the heat change of a reaction occurring at a constant pressure.

measurement units:

                        entropy is measured in joule per kelvin (jk⁻¹)   whereas enthalpy is measured in joule per mole (jmol⁻¹)

requirements:

                            entropy has no requirements or limits, and its change is measured by the division between the heat change of the chemical process and the temperature.

                              in contrast, enthalpy can only be related to the heat change of the reaction under standard conditions.