Nuclear decay occurs according to first-order kinetics. cobalt-60 decays with a rate constant of 0.131 years–1. after 5.00 years, a sample has a mass of 0.302 g. what was the original mass of the sample?

the second one and the forth one are in the purple because they are opinions and the rest are in the yellow

explanation:

adding a(n) to an electric circuit would increase the magnetic field around a wire;

b. solenoid

a solenoid is a type of electromagnet whose purpose is to generate a controlled magnetic field.

if the purpose of the solenoid is instead to impede changes in the electric current, a solenoid can be more specifically classified as an inductor rather than an electromagnet.

the answer is the first electromagnet (a). this is because it has more coils around the ferromagnetic material. increasing the number of coils increases the surface area in which the metal interacts with the current in the coil. this enables more atoms in the metal to become aligned hence becoming more magnetized.