Valence, Sea, Delocalized (Pooled) are the correct answer of this question.
Explanation:
Valence usually reflects the amount of electrons available to fill an atom's topmost shell.An molecule's valence is the amount of protons which can interact with or substitute (explicitly or implicitly) one of the molecule's atoms.
Its electron marine model is a magnetic attachment method in which cations are assumed to be quantum superpositions within a rotating particle' sea.'
Delocalization occurs as orbital angular momentum is distributed through more than one atom.
<u> For example</u>:-bonding electrons can be distributed among many bonded atoms.
Metals are the species which readily lose electrons in order to attain stability. This electron lost by the atom is actually present in its outermost shell which is also known as valence shell.
Ionization energy is defined as the energy required to remove the most loosely bound electron from a neutral gaseous atom.
When we move across a period from left to right then there occurs a decrease in atomic size of the atoms. Therefore, ionization energy increases along a period.
But when we move down a group then there occurs an increase in atomic size of the atoms due to addition of number of electrons in the atoms. Hence, ionization energy decreases along a group.
Thus, we can conclude that metals have low ionization energies and readily share their valence or outer electrons with each other to form an electron sea. These electrons are delocalized or shared among all the atoms that are bonded together and can therefore move freely throughout the metal structure.
Unlike humans, termites are able to extract energy from wood because: they have some microorganisms living in their gut that are able to break down cellulose.
