<h3><u>
The following events are identified as chemical weathering:</u></h3>
- The minerals in a marble statue react with water to form acids and pores in the structure.
- The rocks in a region are streaked orange after being exposed to repeated rains.
<em><u>Reason: </u></em>
When the weathering process occurs due to <em>chemical reaction</em>, then it is considered as chemical weathering.
In <em>the first case</em>, minerals of marble statue are <em>reacting</em> with water to cause weathering. In the <em>second case</em>, due to the <em>acidificaion reaction</em>, the change of the color has happened after exposure to the repeated rains.
<h3><u>
The following events are identified as Mechanical weathering:</u></h3>
- A piece of rock crumbles after being constantly thrashed by strong waves.
- Industrial runoff forms cracks in a rocky structure in its path.
<em><u>Reason:</u></em>
When the rock is broken into simple pieces <em>without any chemical reaction </em>it is considered as mechanical weathering.
In the <em>first cause</em>, due to the <em>abrasion</em> caused by the strong waves, weathering has happened, in the <em>second case</em> industrial run off may be of varying temperature and thus may cause <em>heating or cooling</em> of the rock and causes weathering.
Answer:
D. Discovered chemolithotrophs in natural enviroments.
Explanation:
Sergei Winogradsky was a russian microbiologist. He observed in his research with genus of bacteria <em>Beggiatoa, </em>they were able to oxidize hydrogen sulfide as an energy source. Being the first example known of lithotrophs (organisms that use inorganic substrate in order to obtain energy).
Answer:
Please find the explanation below
Explanation:
Sodium (Na) and Chlorine (Cl) are two electrolytes that play important role in the absorption of water and nutrients in the small intestine. However, as mentioned in the question, the release of sodium and chlorine would lead to a loss of water in the intestines. This is because of the OSMOTIC phenomenon.
Osmosis is the movement of water molecules from a region of high concentration of water/low concentration of solute to a region of low concentration of water/high concentration of solute via a semipermeable membrane. In this case, the Na+ and Cl- ions serve as the solutes, which when released out of the intestine causes the solution in the intestines to be HYPOTONIC compared to the intestinal environment. This causes an OSMOTIC GRADIENT.
This osmotic gradient i.e. difference in concentration provokes osmotic flow of water from the intestines, which has a low solute/high water concentration, to the outside of the intestines, which has a high solute/low water concentration. Hence, water is lost from the intestine because the solute concentration becomes low when sodium and chlorine ions are released.
Answer:
Increasing the alveolar ventilation rate will increase the partial pressure of oxygen in the alveoli.
Explanation:
Alveolar Ventilation rate is the rate of air flow in the alveoli of the lung during normal breathing. It is measured in milliliters of air per minute (mL/min). The alveolar ventilation rate is an important factor in determining the concentrations (partial pressures) of oxygen and carbon dioxide in the functioning alveoli.
A high rate of alveolar ventilation, would result in a rapid influx of oxygen-rich air and efflux carbon dioxide-filled air from the alveoli. This ultimately results in an increase in the concentration of oxygen and a decrease in the concentration of carbon dioxide within the alveoli.
Effects of alveolar ventilation on partial pressures of alveolar carbon dioxide and oxygen (PACO₂ and PAO₂)
If the alveolar ventilation rate is increased (and carbon dioxide production is unchanged), then the partial pressure of carbon dioxide in the alveoli, PACO₂ will decrease.
If the alveolar ventilation rate increases, then the partial pressure of oxygen in the alveoli, PAO₂ will increase.
