Models help us better understand the phenomena
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Answer: D) all of the above</h3>
Explanation:
The lungs pump oxygen in and carbon dioxide out, which goes through the blood stream to help with the cell's energy needs.
Nutrients pass through the blood stream as well. The nutrients start with the digestive system (mouth, esophagus, stomach, small intestine) before going into the blood stream. The nutrients are building blocks to help make new cells when old ones die off.
When those cells die off, the body sheds them like dead skin, but internal dead cells are passed off as waste. This waste and other byproducts the body doesn't need passes through the blood stream as well.
In short, the blood stream is basically the highway to help get desired materials (eg: oxygen and nutrients) and get rid of waste (eg: carbon dioxide and other unwanted byproducts or dead cell material)
So that's why the answer includes A, B and C.
1, 4, 1, 2, 1
Explanation:
We have the following chemical reaction:
MnO₂ + HCl → MnCl₂ + H₂O + Cl₂
To balance the chemical equation the number of atoms of each element entering the reaction have to be equal to the number of atoms of each element leaving the reaction, in order to conserve the mass.
So the balanced chemical equation is:
MnO₂ + 4 HCl → MnCl₂ + 2 H₂O + Cl₂
Learn more about:
balancing chemical equations
brainly.com/question/14112113
#learnwithBrainly
Convert grams —> mols and then mols —> atoms
We know that there are 6.02 x 10^23 atoms/mol
And we know that there are about 160 grams of fe2o3 per mol
So (79g fe2o3)/(160 g/mol) = .49 mol fe2o3
Now we use avogadro’s number to do
(.49 mol fe2o3)/(6.02 x 10^23 atoms/mol) = the answer.
I’ll leave the easy math to you.
Answer:
When there is heat at the bottom of this air or water, the air or water molecules in contact with the heat start to move, and the molecules spread apart. The heated air or water becomes less dense. It rises up until it gets to air or water with the same density as it has, and when it gets there, it pushes the air or water that was there out of the way. At the same time, new air or water fills the space that was vacated when the heated molecules rose up. The air or water that gets pushed out of the way falls down. This sets up a circular motion. Air or water is heated at the bottom, travels to the top, cools, gets denser, falls, is heated again and the whole cycle starts again. Convection does not occur in space because there is no gravity. Ovens work by convection. The heating coils at the bottom of the oven heat the air which climbs to the top, cools slightly, and falls down again.
Explanation:
