In chemical reactions that occur in nature, are atoms and mass conserved

Which of these is the result of scientific research and not engineering? a. a new shoe design that features air cushioning for more comfort and protection b. the creation of glass with uv protection. c. a conclusion about diet commonalities among diabetics. d. the development of a smaller, more compact missile.

Achemist 16 drop copper metal from copper chloride solution. the chemist place is 0.50 g of aluminum foil in a solution containing 0.75 g of copper (ii) chloride. a single replacement reaction takes place. which statement explains the maximum amount of copper that the chemist can extract using this reaction?

  the mississippians were considered to be  horticulturalists, which means they were