Please help ;-: I can't do this

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.

Use the periodic table to complete this equation that represents nuclear fission processesun - ba c 3 n

What is the correct name for the compound cocl3? a) cobalt(i) chloride b) cobalt(i) chlorate c) cobalt(ii) chlorate d) cobalt(iii) chloride