(i) How do you calculate the possible valency of an element from the electronic configuration of its atoms?
(ii) Calculate the valency of element X whose atomic number is 9.
On the basis of electronic configuration, how will you identify the first and the last element of a period?
The stars appear higher from the horizon than they actually are. Explain why it is so.
Write any two differences between binary fission and multiple fission in a tabular form as observed in cells of organisms.
Difference between binary fission and multiple fission are:
Binary Fission |
Multiple fission |
In binary fission, the single cell divides into halves that is into two. |
In multiple fission, a single cell divides into many daughter cells simultaneously. |
Binary fission is of two types; along any plane or longitudinally. Example: Amoeba(along any plane), Leishmania (longitudinally) |
Multiple fission occurs along only one plane. Example: Plasmodium. |