Is a cube of salt being crushed before being stirred into water a physical or chemical change

Describe in detail the melting point behavior of the 80: 20 benzoic acid-mandelic acid mixture

Hey can you me with this i really need y’all

Which of the following has expanded our knowledge of the universe beyond our solar system the most? a. manned space travel b. the hubble space telescope c. the pioneer and voyager missions d. the international space station