Fossils are fundamental to the geologic time scale. The names of most of the eons and eras end in zoic, because these time intervals are often recognized on the basis of animal life. Rocks formed during the Proterozoic Eon may have fossils of relative simple organisms, such as bacteria, algae, and wormlike animals
We need to know the relationship between atmospheric pressure and the density of gas particles in an area of increasing pressure.
The relationship is: As air pressure in an area increases, the density of the gas particles in that area increases.
For any gaseous substance, density of gas is directly proportional to pressure of gas.
This can be explained from idial gas edquation:
PV=nRT
PV=
RT [where, w= mass of substance, M=molar mass of substance]
PM=
RT
PM=dRT [where, d=density of thesubstance]
So, for a particular gaseous substance (whose molar mass is known), at particular temperature, pressure is directly related to density of gaseous substance.
Therefore, as air pressure in an area increases, the density of the gas particles in that area increases.
Agar is used to assist establish an anaerobic environment that promotes nitrate reduction.
Nitrate Reduction test:
- The nitrate in the broth is converted to nitrite by organisms that can produce the nitrate reductase enzyme, which can then be further converted to nitric oxide, nitrous oxide, or nitrogen.
- Anaerobic respiration and denitrification are two processes that can convert nitrate to a variety of compounds.
- While denitrification only reduces nitrate to molecular nitrogen, anaerobic respiration employs nitrate as the bacterium's final electron acceptor, reducing it to a range of chemicals.
- The nitrate reduction test is based on the detection of nitrite and its capacity to produce a red precipitate (prontosil), which is a water-soluble azo dye, when it combines with sulfanilic acid to create a complex (nitrite-sulfanilic acid).
Learn more about the Nitrate reduction test with the help of the given link:
brainly.com/question/11181586
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Answer:
The time taken for the cross mark to disappear decreases steadily down the column.
Explanation:
Now if we look at the data provided, we will discover that the volume of the HCl was held constant while the volume of the thiosulphate was increased steadily and the volume of water decreased steadily.
Recall that a system is more concentrated when it contains less volume of water and more volume of reactants. Hence as the volume of water in the system is being reduced, the concentration of reactants is increased.
It has been established that an increase in the concentration of reactants lead to an increase in the rate of reaction. The disappearance of the cross shows the completion of the reaction between HCl and thiosulphate. The faster or slower the cross disappears, the faster or slower the rate of reaction.
Since increase in concentration of reactants increases the rate of reaction, it is observed that as the volume of the thiosulphate increases (reactant concentration increases) the cross disappears faster (rate of reactant increases). Hence as the volume of thiosulphate increases, it takes a shorter time for the cross to disappear. This implies that the time column in the table (refer to the question) will decrease steadily as the volume of thiosulphate increases.
