Question

Define the following:
i) Valence Shell
ii) Penultimate Shell

Answer 1

Answer:

Valence shell is the outermost shell of every element. Atom of every element have different electronic configurations based on the atomic number of each element. Electronic configuration refers to the distribution of electrons in various shells/orbits/energy levels of every atom.

Answer 2

Answer:

i)Valence shell is the last shell of the atom containing valence electrons. This shell is also known as Ultimate shell.

ii)Penultimate shell is the shell just before the valence or the ultimate shell . i.e., the second last shell of the atom.