A gas with a vapor density greater than that of air, would be most effectively displaced out off a vessel by ventilation.
The two following principles determine the type of ventilation: Considering the impact of the contaminant's vapour density and either positive or negative pressure is applied.
Consider a vertical tank that is filled with methane gas. Methane would leak out if we opened the top hatch since its vapour density is far lower than that of air. A second opening could be built at the bottom to greatly increase the process' efficiency.
A faster atmospheric turnover would follow from air being pulled in via the bottom while the methane was vented out the top. The rate of natural ventilation will increase with the difference in vapour density. Numerous gases that require ventilation are either present in fairly low concentrations or have vapor densities close to one.
18)
a. Ra
d. Ag
19)
a. C
b. Br
c. Mg
20)
a. S
b. Br
c. O
Sorry wasn’t sure about some of them in #18
Hope the notes are helpful.
Answer:
Lines of latitude are used to divide Earth into 24 time zones
Explanation:
Answer:
1. The same pattern of phases repeats monthly
2. Waxing moon phases are visible between the new and full moon
6. A full moon appears toward the middle of a lunar month
Explanation:
Moon has eight phases which is used by the ancient people for the identification of date of the month. Phases of moon tells us about the starting, middle and end of the month. At the starting of the month, waxing crescent appears while at the middle of the month, the moon gains its full shape. Phases which occurs between new and full moon is known as waxing.