Which o the following phrases bet describes a physical model?

a. an exact copy of an object, system, or process
b. a chemical formula
c. a graph or equation
d. a representation of an object, system, or process

Most of the volume of an atom is occupied by the

What sort of waves exhibit the doppler effect?

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.