Tetracarbon hexahyride is a ionic or a covalent bond

Someone me with this: a mineral' is determined by its actomic structure.

In the water cycle , when does water undergo a chemical change

The picture showed normal blood cells which are around and sickle cells which appear much longer people with sickle-cell suffer from the sickle cell anemia which is inherited diseaseit is caused by a change in gene responsible for production of hemo goblin this type of change is known as an