Answer:
7.5 pounds per square-inch
At sea level, one square-inch of any surface has about 15 pounds of air sitting on top of it. At 18,000 feet, that same square inch has only 7.5 pounds per square-inch (psi) exerted on it.
The muscular and skeletal system because we use our brain to move our body it sends a signal to move that muscle that we want to use
<u>Answer:</u> Electrons are taken up by
and they are lost by 
<u>Explanation:</u>
Redox reaction is defined as the reaction in which oxidation and reduction take place simultaneously. It is also called the reaction where the exchange of electrons takes place.
An oxidation reaction is defined as the reaction in which a chemical species loses electrons takes place. In this reaction, the oxidation state of a substance gets increased.
A reduction reaction is defined as the reaction in which a chemical species gains electrons takes place. In this reaction, the oxidation state of a substance gets reduced.
For the given chemical reaction:

The half-reactions for this redox rection follows:
<u>Oxidation half-reaction:</u> 
<u>Reduction half-reaction:</u> 
Hence, electrons are taken up by
and they are lost by 