Which of these refers to the strength of an acid

Idon't really understand this can you me and show your work.☺☺[ chemistry b] subject [ electron transfer in lonic bonds]grade( 12)

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.

What produces wave a)sound b) heats c)transfer of energy d)vibrations