I what process does a solid change directly into a vapor​

Which statement best describes how atoms combine to form sodium chloride (nacl)? a. a positively charged sodium ion and a positively charged chlorine ion form an covalent bond. b. a positively charged sodium ion and a negatively charged chlorine ion form an covalent bond. c. a positively charged sodium ion and a positively charged chlorine ion form an ionic bond. d. a positively charged sodium ion and a negatively charged chlorine ion form an ionic bond.

Start an single atom tab. observe the decay of polonium-211. after each decay, press the reset nucleus button to watch the process again. write a description of alpha decay for po-211

Although respiratory organs vary across different organisms, they all contain respiratory surfaces that have a large surface area and are extremely thin. explain why having an extremely thin respiratory surface with a large surface area is advantageous for the process of gas exchange