Alveoli are tiny sacs within our lungs that allow oxygen and carbon dioxide to move between the lungs and bloodstream
For the first one it’s 69 just count the little lines from the side.
How many protons does Thorium have? 90
How many neutrons does Thorium-234 have? 144
Calculate the mass defect for the isotope thorium-234 1.85864 amu
Explanation:
Mole ratio of NH3 to NaNH2 = 2 : 2.
Moles of NaNH2 produced
= 4.3mol * (2/2) = 4.3mol.