An oil spill occurred in 1969 near the wild harbor salt marsh. researchers have found that several species of salt water marsh plants no longer grow in this area. what is the most likely explanation for these results? all of the original species have hybridized with new ones. pollution from the spill has changed the composition of the marsh. carbon dioxide levels have decreased over the years. the scientists measured the plants incorrectly.

A spill of fuel oil which occurred near the Wild Harbor salt marsh in 1969, affected and contaminated salt marshes with up to 6000 micrograms of oil (per gram) of wet mud. It contaminated also the local populations of Uca pugnax.  Concentrations of oil that spilled greater than 1000 micrograms (ppm) were directly toxic to adults,  100 to 200 ppm, on the other hand, were toxic to juveniles,  so how much more its effect to salt water marsh plants. They were not able to recover from toxins. 

substitution is the answer in this case

water is a polar molecule. a chemical bond is a force of attraction between atoms or ions. bonds form when atoms share or transfer valence electrons. atoms form chemical bonds to achieve a full outer energy level, which is the most stable arrangement of electrons. so, false

explanation:

in h2o molecule, two water molecules are bonded by a hydrogen bond but the bond between two h - o bonds within a water molecule are covalent. the greater the electronegativity difference, the more ionic the bond is. bonds that are partly ionic are called polar covalent bonds. nonpolar covalent bonds, with equal sharing of the bond electrons, arise when the electronegativities of the two atoms are equal.