Note that there are now several types of treatments and medical providers for which Medicare Part B pays 100% of the approved charges rather than the usual 80%. These categories of care include home health care, clinical laboratory services, and flu and pneumonia vaccines.
A giant covalent structure is a three dimensional structure of atoms held together (obviously) by Covalent bonds. These atoms are often all the same-so the elements Silicon and Carbon in the allotropes Diamond and Graphite are Giant Covalent structures.
] , and is very strong. Covalently bonded substances fall into two main types: 1  simple molecules molecules: a collection of two or more atoms held together by chemical bonds. 2  The fundamental unit of compounds and. 3  giant covalent structures.