<span>Mass is a property that determines how much effort it takes to change somethings velocity. Weight is how much downward force does something exert in a gravitational field which is just the amount of gravity time the mass of an object. We use mass interchangeable with weight because everything on earth experiences the same amount of gravity or close to it, and so something that weighs twice as much as something else also has twice as much mass as that something else. Weight can actually vary for the same mass here on earth the strength of gravity changes from one place to another by small amounts, not enough to ruin your cooking recipe instructions, and weight can change dramatically for something that is falling, the strength of gravity for astronauts in orbit is not much reduced in comparison to here on earth, if there was no gravity they wouldn't go around the earth, they are weightless because they are falling and have enough sideways velocity to keep missing the earth, but their mass has not changed, it still requires effort to get them moving or to stop them.
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Answer:
b. cannot exist in optically active form
Explanation:
Stereochemistry is a branch of chemistry that involves the spatial arrangement of the atoms of molecules and studies how this affects the physical and chemical properties of such species.
The correct structure for (2R,3S)‑2,3‑dibromobutane can be seen in the image attached below. Since the compound is a meso compound due to the plane of symmetry. Thus, the compound is achiral. i.e. Compounds that are superimposable on its mirror image. The plane of symmetry is vertical inclined at 90°(i.e. perpendicular) to the page thus goes via the middle of the molecule.