Which of the following allowed Fleming to recognize the pattern of the Penicillium mold killing bacteria? A. He was a scientist trained in the craft of scientific observation.

B. He saw a similar pattern when he used an antibiotic to kill plated bacteria.

C. He knew that Penicillium killed bacteria, so he was prepared to make the observation.

D. He had previously seen a similar pattern when a tear fell on a Petri dish of bacteria.

The de broglie relation λ=h/p can be rewritten in terms of the wave number k as p=kℏ. recall that wave number is defined by k=2π/λ. using the fact that λ=v/f, find the wave numbers k1 and k2 corresponding to frequencies f1 and f2. express your answer as two expressions

What is the relationship between ozone and smog?

Hydroelectricity provides about 7 percent of the electricity generated in the united states. (a) explain how a hydroelectric power plant converts energy stored in water into electricity. (b) identify two factors that determine the amount of electricity that can be generated by an individual hydroelectricity power plant. (c) describe the two main types of land-based hydroelectric power plants. (d) describe two economic advantages and two environmental disadvantages of hydroelectricity.