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A Planaria is a member of which phylum?

The hard substance deposited by the coral animals is ______________.

What is the term that refers to animals that have no true internal body cavity?

Which of these statements is the best explanation of what happens in the photoelectric effect experiment?

In an experiment done in the early 1900’s, Rutherford used a radioactive source to bombard a thin sheet of gold foil with a narrow beam of alpha particles. He carefully measured where these alpha particles went after they hit the foil. Thomson’s plum pudding model was the model of the atom being used at the time. Which of the following explains what Rutherford expected to happen based on Thomson’s model, and why he expected these results?

When a very large number of electrons are sent through the slits, which of these statements best depicts what is observed?

When a single electron is sent through the slits, which of these images best depicts what is observed?

A beam of light from a red laser is allowed to pass through two very closely spaced narrow slits and then fall on a screen (or photographic film). No attempt to measure the light is made before it hits the screen. It produces a series of red spots separated by areas where there is no light, as this picture shows. What does this experiment and pattern demonstrate about the behavior of light? Image Description Five red spots in a horizontal line. The third spot in the middle is the largest. The two spots on either side of the middle get smaller as you move away from the center.

Electrons are sent one at a time through a single slit. This slit is about the width of an atom. The slit can be adjusted to make it wider or narrower. Each electron is later detected using a screen that produces a spot of light wherever it is hit by a charged particle. If the slit is made narrower in an attempt to know exactly where each electron is when it passes through the slit, how does this affect the results?

  In the picture, a sound wave moves from the top of the page towards the bottom and passes through a small hole in a barrier (point 2 on the diagram).  The light areas represent regions of low pressure, and the dark areas represent high pressure.  The following questions ask you to use your understanding of wave behavior to explain what is happening at certain points.    Image Description horizontal evenly spaced bands of dark and light that extend from the top to a barrier with a hole. The distance between two adjacent white bands is labeled 1, the hole is labeled 2. In the next three questions, use your understanding of wave behavior to explain what is happening at certain points.