Iron has many isotopes but only 4 are found in significant amounts in naturally found mixtures. The amounts by mass percent are: 5.845% of 54 Fe (53.9396 amu) 91.754% of 56Fe (55.9349 amu), 2.119% of 57Fe (56.9354 amu) and 0.282% of 58Fe (57.9333 amu).

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.

Acycloalkane molecule contains 8 carbon atoms. how many hydrogen atoms are present in the molecule?

Alculate the concentration of h3o⁺in a solution that contains 5.5 × 10-5m oh⁻at 25°c. identify the solution as acidic, basic, or neutral.a) 1.8 × 10-10m, basicb) 1.8 × 10-10m, acidicc) 5.5 × 10-10m, neutrald) 9.2 × 10-1m, acidice) 9.2 × 10-1m, basic