4. In order to see objects, the wavelength of the light must be smaller than the object. The Bohr radius of a hydrogen atom is 5.291 77 x 10–11 m. a. What is the lowest frequency that can be used to locate a hydrogen atom? b. The visible part of the spectrum ranges from 400 nm to 700 nm. Why aren’t individual atoms visible? 6. Suppose you must decide whether a pre-Columbian mask is genuine before buying it for a museum. It looks genuine, but to ensure its authenticity, you shine X rays of wavelength 1.67x10–10 m on it to see if a certain element is present. What is the frequency of this radiation?

7. Suppose you use ultraviolet light of frequency 9.5x1014 Hz to determine whether a mineral is fluorescent. To what wavelength does this correspond?

8. Meteorologists use Doppler radar to watch the movement of storms. If a weather station uses electromagnetic waves with a frequency of 2.85x109 Hz, what is the length of the wave?

9. PCS cellular phones have antennas that use radio frequencies from 1800–2000 MHz. What range of wavelengths corresponds to these frequencies?
10. Suppose the microwaves in your microwave oven have a frequency of 2.5x 1010 Hz. a. What is the wavelength of these microwaves?
b. The holes in the door of a microwave oven have a radius of 1.2 mm. Why don’t microwaves pass through these holes?
c. Visible light has a wavelength that ranges from 400 nm to 700 nm. Would visible light be able to pass through the holes? Why or why not?

Need asap ! what is the relationship between atmospheric pressure and the density of gas particles in an area of increasing pressure? (2 points) as air pressure in an area increases, the density of the gas particles in that area decreases. as air pressure in an area increases, the density of the gas particles in that area increases. as air pressure in an area increases, the density of the gas particles in that area remains constant. as air pressure in an area increases, the density of the gas particles in that area increases and decreases in an alternating pattern. 3. which of the following correctly describes a way in which earth's atmosphere interacts with the geosphere? (2 points) it contains gases that living organisms breathe. it contains gases that trap incoming solar radiation. it provides a medium for cycles that provide nutrients to living organisms. it provides a medium for water to move between earth's surface and the air. 4. which of the following is considered a drawback to using wind energy as a source of power? (2 points) wind energy is nonrenewable. wind energy produces large amounts of air pollution. 5. a meteorologist predicts that the weather in a region will soon change from clear skies to probable thunderstorms. prior to making this prediction, what did the meteorologist most likely observe on a barometer? (2 points) the barometer fell slightly. the barometer fell substantially. the barometer rose slightly. the barometer rose substantially. 6. which of the following do meteorologists not typically use weather balloons to record? (2 points) atmospheric pressure cloud types humidity temperature 7. during which step in the can crush lab did water vapor force air from the can? (2 points) the can was filled nearly to the top with water. the can was placed on the hot stove top burner for several minutes. the can was removed from the hot stove top burner. the can was placed upside-down in the water-filled pan.

What distance does a car travel as its speed changes from 0 to 20 m/s in 17 s at constant acceleration?

You want to lose weight and have been trying to decide which type of fad diet is best for you. you ask your doctor, who responds that a. fad diets are a temporary fix but generally don't have any side effects b. fad diets can be used several times a year to maintain a healthy weight c. fad diets can be risky for your health and, in the long run, do not work d. fad diets should never be used one right after the other; there should be a break between them select the best answer from the choices provided. a b c d