Answer to Question #149371 in General Chemistry for Drake Hill

Question

What patterns do you notice in the modern day periodic table in terms of protons, electrons, and valence electrons? How might these relate to an element being a metal or a nonmetal?

Answer 1

As you move along the period from RIGHT to LEFT, the metallic properties of the elements are ENHANCED. In the opposite direction, non-metallic ones increase.

This is due to the fact that to the right are elements whose electronic shells are closer to the octet. Elements on the right side of the period are less likely to give up their electrons to form a metal bond and in General in chemical reactions.

From left to right, the core charge also increases in the period. Consequently, the attraction of valence electrons to the nucleus increases and their recoil becomes more difficult.

From left to right, the core charge also increases in the period. Consequently, the attraction of valence electrons to the nucleus increases and their recoil becomes more difficult.

On the contrary, the s-elements in the left part of the table have few electrons on the outer shell and a lower core charge, which contributes to the formation of a metallic bond. With the obvious exception of hydrogen and helium (their shells are close to completion or completed!), all s-elements are metals; p-elements can be either metals or nonmetals, depending on whether they are in the left or right part of the table.

D-and f-elements, as we know, have "reserve" electrons from the "penultimate" shells, which complicate the simple picture characteristic of s-and p-elements. In General, d-and f-elements are much more likely to exhibit metallic properties

Number of protons defines number of electrons in case of not ionized atoms and number of electrons decides about chemical properties of elements.