Insects do not have lungs as we do, nor do they breathe through their mouths. instead, they have a system of tiny tubes, called tracheae, through which oxygen diffuses into their bodies. the tracheae begin at the surface of an insect's body and penetrate into the interior. suppose that a trachea is 1.9 mm long with a cross-sectional area of 2.1 × 10−9 m2. the concentration of oxygen in the air outside the insect is 0.28 kg/m3, and the diffusion constant is 1.1 × 10−5 m2/s. if the mass per second of oxygen diffusing through a trachea is 1.7 × 10−12 kg/s, find the oxygen concentration at the interior end of the tube.

answer; i believe the correct answer is (solid gold);

explanation:

the largest database of organic compounds lists about 10 million substances, which include compounds originating from living organisms and those synthesized by chemists. the number of potential organic compounds has been estimated at 1060—an astronomically high number. the existence of so many organic molecules is a consequence of the ability of carbon atoms to form up to four strong bonds to other carbon atoms, resulting in chains and rings of many different sizes, shapes, and complexities. the simplest organic compounds contain only the elements carbon and hydrogen, and are called hydrocarbons. even though they are composed of only two types of atoms, there is a wide variety of hydrocarbons because they may consist of varying lengths of chains, branched chains, and rings of carbon atoms, or combinations of these structures. in addition, hydrocarbons may differ in the types of carbon-carbon bonds present in their molecules. many hydrocarbons are found in plants, animals, and their fossils; other hydrocarbons have been prepared in the laboratory. we use hydrocarbons every day, mainly as fuels, such as natural gas, acetylene, propane, butane, and the principal components of gasoline, diesel fuel, and heating oil. the familiar plastics polyethylene, polypropylene, and polystyrene are also hydrocarbons. we can distinguish several types of hydrocarbons by differences in the bonding between carbon atoms. this leads to differences in geometries and in the hybridization of the carbon orbitals.

the correct answer is:

a. formation of precipitation