Answer:
C = 18.29 g
Explanation:
Given data:
Mass of beryllium needed = ?
Mass of nitrogen = 18.9 g
Solution:
Chemical equation:
3Be + N₂ → Be₃N₂
now we will calculate the number of moles of nitrogen:
Number of moles = mass/molar mass
Number of moles = 18.9 g/ 28 g/mol
Number of moles = 0.675 mol
Now we will compare the moles of nitrogen and Be from balance chemical equation.
N₂ : Be
1 : 3
0.675 : 3/1×0.675 = 2.03 mol
Number of moles of Be needed are 2.03 mol.
Mass of Beryllium:
Mass = number of moles × molar mass
Mass = 2.03 mol × 9.01 g/mol
Mass = 18.29 g
Answer:
Explanation:
Any genetically based physiological, behavioral, or ecological trait that enables an organism to cope with, and to survive and reproduce in, its environment represents an adaptation.
Qualquer traço fisiológico, comportamental ou ecológico de base genética que permite a um organismo enfrentar, sobreviver e se reproduzir em seu ambiente representa uma adaptação.
Answer:
Option (D) is definitely the answer.
Explanation:
Before going further, it is important to know what buffers and pH represent, which are keywords to answering this question.
Buffers is a special solution that can withstand or resist changes due to pH levels which may be as a result of an introduction of acidic or basic components into the blood. In other words, they maintain the stability of pH level in the human blood.
pH blood levels on the other hand, can be grouped into three: acidity, neutrality and alkalinity. Using a pH scale, one can determine its current level. In the human blood the pH level is near neutral and needs to be on a level near 7.4 in order to avoid a high rise or a drastic fall even if acidic or basic components come in or departs the blood stream.
Therefore, if one of the buffers that contributes to pH stability in human blood is carbonic acid, which is as a result of a combination of carbon dioxide and water in the blood stream. On getting to the lungs it is converted to water and subsequently released as waste. Maintaining this stability will definitely be to decrease the concentration of carbonic acid and increase that of water instead.
