Answer:
<h2>Normal quiet expirarion of air is known as Tidal volume which is equal to 500 mL .</h2>
Explanation:
Normal quiet expiration or Tidal volume is a expiration of air with each normal breath . This is about 500 mL . It is composed of about 350 mL of alveolar volume and about 150 mL of dead space volume . The alveolar volume consist of the air that reaches the respiratory surface of alveoli and involve in gaseous exchange . The dead space volume consist of air that does not reach the respiratory surfaces . The lowest value is of Tidal volume . There is an extra amount of air that can be expired forcibly after a normal expiration i.e., known as expiratory reserve volume which is equal 1000 mL of air .
Answer:

Explanation:
As we know that the formula for pH is
![pH = -[log H+]\\](https://tex.z-dn.net/?f=pH%20%3D%20-%5Blog%20H%2B%5D%5C%5C)
It is also given in the question that one pH unit represents the 10 fold change in the concentration of hydrogen ion.
Now for lemon juice whose pH is 2, hydrogen ion concentration is equal to

And for pure water whose pH is
, hydrogen ion concentration is equal to

Thus, the H+ ion concentration in lemon juice is
times greater than the pure water.
Burning fossil fuels will produce carbon dioxide which is a global gas causing global warming . Global warming causes the sunlight to be trapped in the atmosphere of the earth which will cause the temperature of the earth to increase. so the polar ice will melt and the sea level will increase