What is the speed of a train that goes 250miles n 5hours

If one fission reaction of a uranium-235 atom produced two neutrons, how many neutrons would be released if the chain reaction occurred three more times?

An ice cube with a volume of 45.0ml and a density of 0.9000g/cm3 floats in a liquid with a density of 1.36g/ml. what volume of the cube is submerged in the liquid

The activation energy for a(n) is quite large and usually takes extra energy from the environment, it is normally not a natural spontaneous process. combustion reaction endothermic reaction exothermic reaction catalyzed reaction