Answer:
Answer: (1R,2S) / (1S, 2R) , (1R,2R) / (1S, 2S)
Explanation:
Sodium borohydride reduction of benzoin will give four possible stereo isomers out of which are (1R,2S) - (1S, 2R) isomers and (1R,2R) - (1S, 2S) isomers which are known as enantiomers.
In general enantiomers show single spot in the TLC as they do not show any difference in Rf value (i.e) (1R,2S) - (1S, 2R) isomers show only one spot although they are two compounds and also (1R,2R) - (1S, 2S) isomers also show one spot. That is the reason why you are observing two spots in the TLC ( of reaction mixture) other than starting materilal.
A chemical change results from a chemical reaction, while a physical change is when matter changes forms but not chemical identity.
Examples of chemical changes are burning, cooking, rusting, and rotting.
Examples of physical changes are boiling, melting, freezing, and shredding.
Answer:
a. mixtures are created through physical changes and compounds are created through chemical reactions
Explanation:
Answer: 39 electrons
Explanation: Subtract 79 by 40 to get the atomic number (amount of protons) which is 39. The number of electrons must be the same as the number of protons if it's not an ionic compound so the amount of electrons is the same amount of protons.