Answer:
3 types are recombination,mutation and immigration
The level of electrons involved is equal to its valency....
B since there are two nuclear envelopes it is the last stage -- telophase
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.
Tungsten (W) has six electron shells. You get this number by counting down to the row the element is on. The row number is the number of electron shells.
