Epoxides are cleaved by acid as are other ethers, but milder conditions are sufficient due to ring strain. The mechanism of acid-catalyzed epoxide opening is complex. They seem to be neither purely SN1 nor SN2, but instead to be midway between these two extremes and to have characteristics of both mechanisms. When both epoxide carbon atoms are either primary or secondary, attack of the nucleophile occurs primarily at the less substituted site, an SN2-like result. On the other hand, when one of the epoxide carbons is tertiary nucleophilic attack occurs primarily at the more substituted site, an SN1-like result. Draw curved arrows to show the movement of electrons in this step of the mechanism. Arrow-pushing Instructions

Is a measure of the resistance to flow. a high liquid has a high resistance to flow and flows slowly. the ancients thought everything in the world was made of 4 we now know that there are 94 naturally occurring and scientists have created another 24 i am certain they will create even more. honey flows slowly because it has a high to flowing. a can be separated by physical means because it contains more than one pure substance and 2 pure substances are not chemically bonded to each other. a cannot be separated by physical means. all matter is made up of all elements are with the same number of protons. if it is just a single or many bonded together, if all of them have the same number of protons, it is an element. in a piece of pure iron metal, all the are joined together, that piece of iron metal is called elemental iron. a single of iron is called elemental iron. a mixture has differences from place to place. we might need a microscope to see them or they might be obvious to the unaided eye. there are surfaces separating it into different phases. a mixture is the same everywhere. it is uniform. there are no surfaces separating it into different phases. if different kinds of atoms (different elements) are bonded together by their electrons, it is called a there are physical means of to isolate the different pure substances in a mixture and there are chemical means of to isolate the different elements in a compound. 1. element 2. compound 3. mixture 4. heterogeneous 5. homogeneous 6. pure substance 7. atoms 8. separation 9. viscosity 10. resistance