The electrons in the outermost shell of the covalent compounds are shared by nearby atoms. As there are no free electrons for conducting electricity, the covalent compounds are perfect insulators at absolute zero. As the temperature increases, some electrons move from valence band to conduction band. This gives rise to conductivity. But as the numbers of charge carriers are very low, covalent compounds are poor conductors. On the other hand metals are good conductors cause of their bonding. Metallic bonding consists of a sea of electrons rather than discreet bonds. The free electrons are able to move freely. Since electricity and heat need electrons to move, the bonding promotes conductivity.
Answer:
A
Explanation:
1. The colour is non metallic.
2. properties of metal solidness is not there, because of results of hammer experiment.
3. Physical consistency is not solid.
Etc.
ECM is the extracellular matrix, or the set of extracellular molecules secreted by cells with the purpose to support surrounding cells. In plants the cell wall is the ECM and in mammals ECM can be in the form of fibrils and may constitute a significant portion of the bulk of the organism and it also referred as connective tissue.
The nitrogen cycle. Animal and plant waste decomposes and adds nitrogen to the soil, which bacteria convert into a form that plants use to grow. Animals eat the plants, which completes the cycle.
