Answer:
Because there is trapped air inside the cube of ice
Explanation:
when water freezes it has water molecules and air molecules and as it freezes they move slower and slower until it freezes and they become stuck
Answer:
The structure of the salt is attached.
Explanation:
Physostigmine, an alkaloid obtained from a West African plant (Physotigma venenosum),is used in the treatment of glaucoma. Treatment of physostigmine with methyl iodide gives a quaternary ammonium salt. What is the structure of this salt?
The structure of the salt is attached
The correct option is D.
The hydrogen atoms that are attached to the nitrogen atom in the ammonia molecule are capable of forming hydrogen bond. The hydrogen bond that exist in the ammonia molecule is the reason why it shows higher boiling point compare to the other hydrides. Hydrogen bond occur in ammonia because ammonia is one of the most electronegative elements.