I think the answer is choice D
Answer:
Ionic
Explanation: Ionic compounds tend to be hard and brittle while covalent compounds tend to be softer and more flexible.
Hope this helped!
Answer:
not quite sure what you meant by the question but I think the answer you're looking for is biomass? not sure though
Answer:they have the same number of electrons in the valence shell
Explanation:
I'm guessing D or C, remember that the noble gases cannot combine
