What are some example reactions that represent the four indicators of a chemical change?

Reaction rate depends on how many molecules are coming into contact with each other with enough energy to react. increasing the temperature of the reactants will increase -

Americium-241 undergoes fission to produce three neutrons per fission event. if a neutron-absorbing material is mixed in with this sample so that the rate of neutron production drops down to 1.8 neutrons per fission event, which will be effective at achieving a critical mass? check all that apply. remove a deflective shield surrounding the sample. remove absorbent material mixed in with the sample. compress the sample of americium-241.

How will the volume of a gas be affected if the pressure is tripled, but the temperature remains the same?