Valence electron - Wikipedia
All atoms are made up of a positively charged nucleus surrounded by negatively charged electrons. The outermost electrons -- the valence. The number of electrons in an atom's outermost valence shell governs its bonding behaviour. Elements whose atoms have the same number of. When a chemical bond forms, some valence electrons are either shared or transferred between atoms. Only the in an ionic bond. When the difference in.
This tendency is called the octet rulebecause each bonded atom has eight valence electrons including shared electrons. The most reactive kind of metallic element is an alkali metal of group 1 e.
An alkaline earth metal of Group 2 e. Within each group each periodic table column of metals, reactivity increases with each lower row of the table from a light element to a heavier elementbecause a heavier element has more electron shells than a lighter element; a heavier element's valence electrons exist at higher principal quantum numbers they are farther away from the nucleus of the atom, and are thus at higher potential energies, which means they are less tightly bound.
A nonmetal atom tends to attract additional valence electrons to attain a full valence shell; this can be achieved in one of two ways: An atom can either share electrons with a neighboring atom a covalent bondor it can remove electrons from another atom an ionic bond. The most reactive kind of nonmetal element is a halogen e.
How do valence electrons affect chemical bonding?
Such an atom has the following electron configuration: To form an ionic bond, a halogen atom can remove an electron from another atom in order to form an anion e. To form a covalent bond, one electron from the halogen and one electron from another atom form a shared pair e. Within each group of nonmetals, reactivity decreases with each lower rows of the table from a light element to a heavy element in the periodic table, because the valence electrons are at progressively higher energies and thus progressively less tightly bound.
In fact, oxygen the lightest element in group 16 is the most reactive nonmetal after fluorine, even though it is not a halogen, because the valence shell of a halogen is at a higher principal quantum number. In these simple cases where the octet rule is obeyed, the valence of an atom equals the number of electrons gained, lost, or shared in order to form the stable octet. However, there are also many molecules which are exceptionsand for which the valence is less clearly defined.
Electron Shells Every element is surrounded by a certain number of electrons that populate electron orbitals. Each orbitals requires two electrons to be stable, and the orbitals are organized into shells, with each successive shell being of a higher energy level than the previous one. The lowest shell contains only one electron orbital, 1S, and, thus, requires only two electrons to be stable. The second shell and all those that follow contains four orbitals -- 2S, 2Px, 2Py and 2Pz one P for each axis: Going down the rows of the Periodic Table of the Elements, a new shell of 4 electron orbitals, with the same setup as the second shell, exists around each element.
For example, Hydrogen in the first row has only the first shell with one orbital 1S while Chlorine in the third row has the first shell 1S orbitalthe second shell 2S, 2Px, 2Py, 2Pz orbitals and a third shell 3S, 3Px, 3Py, 3Px orbitals. Sciencing Video Vault Note: The number in front of the each S and P orbital is an indication of the shell in which that orbital resides, not of quantity.
Each of these electron pair so that electron pair would be represented as a covalent bond. This would be represented as a covalent bond. That would be represented as covalent bond.
How do valence electrons affect bonding? | Socratic
That would be represented as a covalent bond. Each of these bonds or the sharing of essentially two electrons, the two electrons. Carbon can feel like it has two, four, six, eight electrons even it's sharing. Each of the hydrogens can feel like they have two electrons which gets it into a more stable state. In any of the elements, in carbon's group, they are all going to have four Valence electrons. For example tin, even though neutral tin is going to have 50 electrons, the Valence electrons, the ones that are going to react are going to be the one, two, three, four in its outer shell.
People even think, there could be life forms in other planets that aren't based on carbon but actually are based on silicon because silicon would have similar types of bond that it can form similar types of structures to carbon for this exact reason.
Now what about, I kind of said that you have your transition metals, you d-block right over here and actually your f-blocks are going to be thrown in here as well and these are special cases. These get a little bit more involved because as we already learned that once you're in the fourth period, Let's say we want to do the electron configuration.How to Find Valence Electrons! (and Total Electrons)
Iron's electron configuration, we could start with argon as a base and then we're going to go four S two and then we're now in the d-block but we're not going to fill the four D suborbital. We're not going to back up and back fill into the three d-suborbital. It's one, two, three, four, five, six. It's three D six.
This is where this gets a little bit more vigorous. What are the highest energy electrons? Well those are these D electrons right over here. What are the furthest out? Well they're the ones in the fourth sub shell, these four S two. That's why iron's reactivity is a little bit at least based on just this superficial electron configuration.
It's a little bit harder to predict. Iron is known to lose one electron, known to lose two electrons, known to lose three electrons and so those could be some combination of these highest energy electrons, both the ones that are furthest out and the ones that are highest energy.
Iron becomes all the transition elements, figuring out the Valence electrons, the electrons that are most slightly right becomes a little bit hard to predict.
Some people, some even textbooks will say, "Oh, all the transition metals" "have two Valence electrons" "because they all get the four S two" "and then they're back filling. Sometimes it does it otherwise but even for the other transition elements like say iron is not necessarily the case so these are the one, the only two electrons that are going to react. You might have some of your D electrons, your three D electrons which are high energy might also be involved in reaction.