How to predict the product of synthesis

When two elements combine in a synthesis reaction, the only product that can be made is a binary compound: A + B = AB. If two compounds combine in a synthesis reaction, they can form a ternary compound, which is a compound made up of three elements: AB + BC = ABC.

radioactive decay occurs in unstable atomic nuclei – that is, ones that don't have enough binding energy to hold

the nucleus together due to an excess of either protons or neutrons.

d: the voltage of the secondary coil is less than that of the primary coil.

im not suree sorry if wrong