Converting uranium to thorium by decreasing the number of protons from 92 to 90 and decreasing the number of neutrons from 146 to 144 is an example of what type of decay?
a. alpha decayb. beta decayc. positron emissiond. electron capture

I think the above conversion is an example of A.) ALPHA DECAY.

In Alpha decay, nucleus releases an alpha particle, Helium. When the alpha particle is released the remaining nucleus weighs less due to the decrease in neutrons and protons have also decreased in number.

Yes i think so not 100 percent sure though

29.1-12=17.1the answer is this one