Answer:
i) Upwards delivery
ii) Downwards delivery
Explanation:
The methods used in the collection of gases are quite different depending on the state of the gas. The solubility and density of gases are the factors that determine the method of collection to be used.
Upwards delivery is used to collect gases that are soluble in water and lighter compared to air. Examples of these kind of gases include; Cl2 and SO2
Downwards delivery is used to collect gases that are soluble in water and denser than air. An example of this kind of gas is ammonia gas, NH4.
Given the wavelength of the yellow light (700 nm. in this case) we can find the frequency
<span>by dividing the speed of light c by the wavelength w, that is: f = c/w and we know that </span>
<span>c is equal to 2.998 * 10**8 meters per second. </span>
<span>So the frequency f = (2.998 * 10**8) / (7.0 * 10**-7) = 4.283 * 10**14 cycles per sec. </span>
<span>(or Hz.) Since the threshold frequency of Cs is 9.39 * 10**14 Hz, the red light doesn't </span>
<span>have a high enough frequency (or energy) to cause electron emission. </span>
<span>Hope this answers your question.</span>
The sharing of ideas and experimental findings with other through writing and speaking is called, COMMUNICATION
