What shape uses the smallest amount of material when creating a critical mass?

The smallest amount of material that can sustain a chain reaction. :)

The smallest amount of a fissionable material that will produce a self-sustaining chain reaction is called the critical mass. This mass of affected by geometry and other factors such as temperature, pressure, and moderator.

The critical mass. With an amount of U-235 or Pu-239, the smallest critical mass will be a sphere. For a nuclear reactor, it will be the minimum number of fuel assemblies loaded to produce a chain reaction.

Critical mass is the minimum amount of nuclear material needed to cause a chain reaction to continue without stopping.

We know that critical mass can be achieved in a nuclear reactor. If it could not, we'd not be able to get a chain reaction and generate heat to generate power. Reactors don't have critical mass when the control rods are in, but pull the rods, start the reactor up and away you go!

Critical Mass is that minimum amount of fissionable material needed to maintain a chain reaction

If the universe is ever to stop expanding and start contracting there has to be a certain amount of material (mass). This amount is called the 'critical density'. So far as is known to date the universe does not have sufficient mass to stop expanding, hence it is below the critical density.

If it's a molecular compound, the smallest amount would be one molecule. If it's an ionic compound, the smallest amount is a formula unit.

This amount is the molecule.

The words fissile and fissionable are not generally taken to mean the same thing. Fissile materials can sustain a chain reaction with low energy neutrons. Fissionable materials can sustain a chain reaction, but only if the energy of the neutrons present is sufficiently high. Critical mass is the amount of material needed, in ideal circumstances, to start a chain reaction without neutrons other than those produced internally. 235U is fissile, and has a critical mass…

This amount of material is the mass.

The amount of material in a substance is mass.

their is no radioactive material in the construction of any bomb its just a bunch of atoms creating friction and being so excited that they explode in a devistating amount of force.

The amount of one material in a certain volume of another material?

Solubility measures the amount of one material that will dissolve in another material.

The smallest amount is 1.

It is the minimum value of the set.

Mass measures the amount of matter in an object or material.

The question refers as to what measures the amount of one material that will dissolve in another material. The answer is solubility.

The ingredients section on a food label lists from greatest amount to smallest amount all ingredients and chemicals in that food.

A bit is the smallest amount of info a computer can store...

The smallest amout of rainfall is zero-- none at all.

The smallest will be 1 ml +/- 0.01.

The number of moles of the material.

It means the smallest amount.