Which combination makes up most of the mass of an atom? A. Electron and proton
B. Electron and neutron
C. Proton and neutron
D. None of these make up atom’s mass

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.

Air can be considered a mixture. which statement does not explain why?

Which liquid (h2o, h2o + soap, or h2o + salt) has the strongest cohesion and adhesion? (need now plz)