Can pure substances made from compounds be physically separated?

Ageologist determines that a sample of a mineral can't be scratched by a steel nail but can be scratched by a masonry drill bit. based on this information, the sample mineral has to be softer than a. orthoclase. b. fluorite. c. apatite. d. corundum.

What does a complete balanced chemical equation include? a. exothermic coefficients b. endothermic coefficients c. valence electrons d. molar coefficients

The number at the end of an isotope’s name is the number.