URGENT TIMED EXAM 4.The quantum mechanical model of the atom

•is concerned with the probability of finding an electron in a certain position

. was proposed by Neils Bohr

•defines the exact path of an electron around the nucleus

• has many analogies in the visible world

Infants born with severe respiratory problems are sometimes given liquid ventilation: they breathe a liquid that can dissolve more oxygen than air can hold. one of these liquids is a fluorinated compound, cf3(cf2)7br. the solubility of oxygen in this liquid is 66 mlo2 per 100 ml liquid. in contrast, air is 21 % oxygen by volume. calculate the moles of o2 present in an infant's lungs (volume: 12 ml ) if the infant takes a full breath of air. assume a pressure of 1 atm in the lungs.

1) these are barrel shaped microtubules in most animal cells, that organize the spindles during cell division

Answer asap : ( a. how does mucus prevent the entry of pathogens? b. describe two ways white blood cells protect us from pathogens.