Explanation:
from the graph study about oxygen content of Earth's atmosphere, we can understand that
1)
4 billions year ago = None, 3 billions year ago = Cyanobacteria and Archaea , 2 and 1 billions year ago = Bacteria and Green algae , 500 Ma = invertebrate fossils started to existence. Early land plants came in to existence around 398 MA that is Devonian. Dinosaurs are came in to existence during Triassic and Jurassic that is around 251 Ma. Man and animals are recent organism came under Holocene that is 11000 years ago.
2)
The first cells on the earth are anaerobic microorganisms, as the CO2 level is too high they survive by using CO2.
3)
Starting around 2.7 billion years ago, photosynthesis by Cyanobacteria and later plants , pumped “OXYGEN” in to the atmosphere. This caused the decline of anaerobic bacteria and allows the diversification of animals as seen in “CAMBRIAN” around 500 millions year ago.
Early vascular plants “CAPTURED” CO2 starting before the Carboniferous period that began around 350 millions year.Leading to lower temperatures and allowing and allowing the seed plants to outcompetes seedless plants.
Modern human activities has raised both “CO2 and METHANE” level in the atmosphere to over leading to higher temperature and extinction of other species.
Answer:
B,C,D
Explanation:
The yield of CCl4 depends on the amount of CH4 in a 1:1 ratio. The amount of Cl2 is twice that of CH4 hence some must be left over. To ensure that all the Cl2 is used up, more CH4 must added to the system.
As number of gaseous moles in reactant and prodict are same that is 4
So No change will occur
Answer:
Al 72.61%
Mg 27.39%
Explanation:
To obtain the mass percentages, we need to place the individual masses over the total mass and multiply by 100%.
If we observe clearly, we can see that the parameters given are the moles. We need to convert the moles to mass.
To do this ,we need to multiply the moles by the atomic masses. The atomic mass of aluminum is 27 while that of magnesium is 24.
Now, the mass of aluminum is thus = 27 * 0.0898 = 2.4246g
The mass of magnesium is 0.0381 * 24 = 0.9144g
We can now calculate the mass percentage.
The total mass is 0.9144 + 2.4246 = 3.339g
% mass of Al = 2.4246/3.339 * 100 = 72.61%
% mass of Mg = 0.9144/3.39 * 100 = 27.39%
4.4moles of oxygen atoms
Explanation:
Given parameters:
Mass of MgSO₄ = 132.2g
Unknown:
Number of moles of oxygen atoms = ?
Solution:
The number of moles is the quantity of substance that contains the avogadro's number of particles.
To solve for this;
Number of moles = 
Molar mass of MgSO₄ = 24 + 32 + 4(16) = 120g/mole
Number of moles = 
= 1.1 moles
In
1 moles of MgSO₄ we have 4 moles of oxygen atoms
1.1 moles of MgSO₄ contains 4 x 1.1 moles = 4.4moles of oxygen atoms
learn more:
number of moles brainly.com/question/1841136
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