- Science AP®︎/College Chemistry beta Atomic structure and properties Valence electrons and ionic compounds Valence electrons and ionic compounds Worked example: Finding the formula of an ionic compound.
- Valence, in chemistry, refers to a number assigned to elements that reflects their ability, or capacity, to react (combine) with other elements. It also refers to the type of reactions the element will undergo.
Valence bond (VB) theory assumes that all bonds are localized bonds formed between two atoms by the donation of an electron from each atom. This is actually an invalid assumption because many atoms bond using delocalized electrons. In molecular oxygen VB theory predict that there are no unpaired electrons. VB theory does a good job of qualitatively describing the shapes of covalent compounds. While Molecular Orbital (MO) theory is good for understanding bonding in general. It is more difficult to learn, but predicts the actual properties of molecules better than VB theory. MO theory actually predicts electron transitions because of the differences in the energy levels of orbitals in the molecule. MO theory has been more correct in numerous instances and for this reason it is preferred.
Valence Bond theory describes covalent bond formation as well as the electronic structure of molecules. The theory assumes that electrons occupy atomic orbitals of individual atoms within a molecule, and that the electrons of one atom are attracted to the nucleus of another atom. This attraction increases as the atoms approach one another until the atoms reach a minimum distance where the electron density begins to cause repulsion between the two atoms. This electron density at the minimum distance between the two atoms is where the lowest potential energy is acquired, and it can be considered to be what holds the two atoms together in a chemical bond.
There are 7 valence electrons because the highest energy level, 3, has 7 total electrons (5 plus 2 is 7). For calcium, which has an atomic number of 20 and therefore 20 electrons, find calcium on.
- d-orbital Hybridization is a Useful Falsehood
- For main group molecules, chemists (like Pauling) thought a long time ago that hypervalence is due to expanded s²p⁶ octets. The consensus is now clear that d orbitals are NOT involved in bonding in molecules like SF₆ any more than they are in SF₄ and SF₂. In all three cases, there is a small and roughly identical participation of d-orbitals in the wavefunctions. This has been established in both MO and VB theory.
- Delocalization of Electrons
- To introduce the concept of electron delocalization from the perspective of molecular orbitals, to understand the relationship between electron delocalization and resonance, and to learn the principles of electron movement used in writing resonance structures in Lewis notation, known as the curved arrow formalism.
- Hybridization
- Hybridization is the idea that atomic orbitals fuse to form newly hybridized orbitals, which in turn, influences molecular geometry and bonding properties. Hybridization is also an expansion of the valence bond theory. In order to explore this idea further, we will utilize three types of hydrocarbon compounds to illustrate (sp^3), (sp^2), and (sp) hybridization.
- Hybridization II
- Hybrid Orbitals in Carbon Compounds
- Diamond crystals such as the one shown here are appreciated by almost everyone, because of their hardness, sparkle, and high value. They are also important in many technical applications. However, in terms of chemistry, diamonds consist of only carbon atoms, except for impurities. Like diamond, the chemistry of carbon is indeed very interesting and valuable.
- Overview of Valence Bond Theory
- Valence Bond (VB) Theory looks at the interaction between atoms to explain chemical bonds. It is one of the two common theories that helps describe the bonding between atoms. The other theories is the Molecular Orbital Theory. Take note that these are theories and should be treated as such; they are not always perfect.
- Resonance
- Resonance structures are used when a single Lewis structure cannot fully describe the bonding; the combination of possible resonance structures is defined as a resonance hybrid, which represents the overall delocalization of electrons within the molecule. In general, molecules with multiple resonance structures will be more stable than one with fewer and some resonance structures contribute more to the stability of the molecule than others - formal charges aid in determining this.
What does Valence mean in chemistry?
1 Answer
Valence is a term that deals with the electrons that are most typically involved in the bonding characteristics of an atom. These electrons are found in the s and p orbitals of the highest energy level of the electron configuration for the element.
The valence shell can hold 2 electrons in the s orbital representing the first two columns of the periodic table and 6 electrons in the p orbital found in columns 13 - 18 of the periodic table.
Some examples would include:
Valence Number
Mg
Valence Chemistry Table
Se
Each element in the periodic table will have the same number of valence electrons as the elements in the same column. All Alkai Metals (Li, Na, K, Rb) have 1 valence electron. All Halogens (F.Cl, Br, I) have 7 valence electrons. All of the Noble Gases (Ne, Ar, Kr Xe) will have 8 valence electrons and fulfill the
Chemical Valence
Atoms try to gain or lose electrons to fulfill the
Valence Chemistry Meaning
I HOPE THIS WAS HELPFUL.
SMARTERTEACHER
Related questions