Moles are the ratio of the mass and the molar mass of the substance given and is estimated in mol. The moles that the lungs contain when it is full is 0.12 moles.
<h3>What is the relation of the volume and moles?</h3>
Moles of the substances are directly proportional to the volume of the substance and can be shown as,

Here,
Initial volume
= 2.9 L
Final volume
= 1.2 L
Initial moles = 
Final moles
= 0.049 mol
Substituting values in the equation:

Therefore, the number of moles in the lungs are 0.12 moles.
Learn more about moles and volumes here:
brainly.com/question/13909347
D is the only choice here that is appropriate given neutrons' lack of charge
<span>The correct answer is b. Radon. Oxygen, Hyrdrogen, and Boron, are not radioactivel ike Radon and it regenerates quickly meaning that even though it has a short half-life period, it stays for a long time once released. It also has no taste so it's difficult to notice without proper gear because you can't feel it.</span>
The answer to this question would be: BaCl 2
Barium is an alkali metal with 56 atomic number. Barium located in the group 2 of the periodic table because it has 2 valence electrons. Chlorine is a nonmetal that has 1 valence electron. When react, it would need 2 chlorine for each barium as the valence electron of barium is twice the chlorine.