Atomic Bonds Flashcards
Two types of forces
Attractive and Repulsive
The magnitude of each depends on the separation or ____
Interatomic Distance
Is the sum of both attractive and repulsive compopnents
Net Force
A state of _____ exists when Fa and Fr balance or become equal.
Equilibrium
Equilibrium spacing is labeled as _____
r0
Corresponds to the energy at this minimum point
Bonding Energy
Three types of primary or chemical bonds found in solids
Ionic, Covalent, Metallic
It is always found in compounds and are composed of both metallic and nonmetallic elements, elements that are situated in the horizontal extremities of the periodic table
Ionic Bonding
An atom with an electrical charge
Ions
The attractive bonding forces are _____
Coulombic
The magnitude of the bond is equal in all directions around an ion
Nondirectional
Predominant bonding in ceramics
Ionic Bonding
Stable electron configurations are assumed by sharing of electrons between adjacent atoms
Covalent Bonding
In this model, these valence electrons are not bound to any particular atom in the solid and more ore less free to drift throughout the entire metal
Metallic Bonding
The remaining nonvalence electrons and atomic nuclei in metallic bonding form what are called _____
Ion Cores
Possess a net positive charge equal in magnitude to the total valence electron charge per atom
Ion Cores
Maximum number of valence electrons for metallic materials
3
% Ionic Character of Covalent Bonds
{ 1 - exp[ -(0.25 ) (Xa-Xb)^2) ] } x 100
they may have high melting temperatures as in diamond or low as in bismuth
Covalent Bonding
may be very strong as in diamond or as weak as in graphite
Covalent Bonds
Bonds that are weak in comparison to the primary or chemical ones
Secondary Bonds or van der Waals
Secondary bonds are also known as
van der Waals
exists between virtually all atoms or molecules, but its presence may be obscured if any of the three primary bonding types is present
Secondary Bonding
Exists whenever there is some separation of positive and negative portions of an atom or molecule
Dipole
A special type of secondary bonding to exist between some molecules that have hydrogen as one of the constituents
Hydrogen Bonding
Occurs when a normally electrically symmetric atom or molecule undergo temporary distortions in its electron cloud resulting in the creation of small electrical dipole
Fluctuating Induced Dipole Bond
Exist by virtue of an asymmetrical arrangement of positively and negatively charged regions
Polar molecule-induced Dipole Bonds
Exist between adjacent polar molecules and are the strongest type of secondary bonds
Permanent Dipole Bonds
