Tutor profile: Deirdre W.
What are some strategies to improve your score in the Reading section?
Practice skimming the passages, reading the questions, and then going back to read the passage thoroughly with those questions in mind. Practice coming up with your own answer to the questions before you read the options, so that you don't get influenced by the options. Eliminate wrong answers first, as this will help you select the correct answer out of what remains if you have to guess.
What are some of the well known historical models of the atom?
The plum pudding model: Electrons are thought to float around in a "soup" of positive charge. Rutherford's model: Also known as the planetary model. Electrons are thought to orbit the nucleus of positive charge, much like planets orbit the sun. Bohr's model: A slight improvement to Rutherford's model. Electrons still orbit the nucleus, but are thought to do so at specific distances (levels), which reflects the amount of energy they release as light.
One postulate of special relativity is that the speed of light is the same for all observers. The speed of light is related to it's frequency and wavelength by the equation c = λ*f. When a monochromatic light source moves toward an observer, its wavelength (λ) appears to be shorter than the value measured when the source is at rest. Does this mean that its speed decreases accordingly, and violates the hypothesis that the speed of light is the same for all observers?
No, because the frequency (f) increases to compensate, thus keeping the speed of light steady!
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