Answer:
3
three half-filled orbitals each capable of forming a single covalent Bond and an additional lone - pair of electrons
Chlorine will have the slowest rate of diffusion because it has the highest relative molecular mass of 71 followed by O₂ with 32, then Neon 20 then He with 2
The rate of diffusion of a gas is inversely proportional to the square root of its relative molecular mass.
Their lungs would try to expand to about 4 timed the normal volume which would force air into the various body tissues. this can cause a lung expansion injury and it could case air embolism. Air embolism is when air bubbles get trapped in blood vessels. This can lead to a blockage which will could be fatal.