You know that neutrons are found in the nucleus of an atom. Under normal conditions, protons and neutrons stick together in the nucleus. During radioactive decay, they may be knocked out of there. Neutron numbers are able to change the mass of atoms, because they weigh about as much as a proton and electron together.
The seeds she planted in the mud grew quicker because the mud is holding nutrition for the corn. The soil is a good guess to make, but the mud is more dense and moist. The water wouldn't have had more nutrients than the mud, just because the mud holds breakdown matter and other things from other plants.
The answer is urethra.
It is known that the kidneys are responsible for filtration of metabolic wastes from the blood and form urine. Urine is transported through the ureters to the urinary bladder. From the urinary bladder, urine is transported to the outside of the body by the urethra.
