Electromagnetic and mechanical waves have different characteristics that make them advantageous for certain applications. select the reasons that mechanical waves, such as ultrasound, are used for soft tissue imaging and to identify fractures in metals

Examine the equation. 23490th→23088ra+42he what kind of barrier would you need to block the radioactive particles from this reaction? a.a piece of paper b.a sheet of aluminum foil c. a two-inch block of lead d. a solid concrete block

An object's buoyant force and weight mean the same thing.a. trueb. false

The first-order reaction a→2b+c has rate constant 0.538 s−1. if the initial concentration of a is 0.867 mol l−1, what is the half-life of the reaction in seconds? remember to use correct significant figures in your answer (round your answer to the nearest hundredth). do not include units in your response.