Module 1 Flashcards
Refers to the electrostatic force holding two ions together due to their differing charges
Ionic bond
___ result from the transfer of one or more electrons from one atom to another
Ions
Ions that lose an electron
Cation
A non-metal atom that gains an electron
Anion
Ionic bonding is actually a CONSEQUENCE
of ___
Ionization
___ have a tendency to lose electrons
Metals
___ have a tendency to gain electrons
Non-metals
“To have eight valence electrons”
Octet rule
Hydrogens love having a ___ bond
Single
Covalent bond classifications
Overlap of electron clouds which allow bond rotation
Sigma bonds (single bonds)
Covalent bond classifications
Bonds which arise from electron clouds which do not allow bond rotation
Pi bonds
Covalent bonds are also known as?
Molecular orbitals
Properties of a Covalent Bond
Refers to the number of electron pairs shared by a pair of atoms involved in a covalent bond
Bond order
Properties of a Covalent Bond
Refers to the energy required to overcome the forces of attraction between the atoms, Silberberg (2013)
Bond energy
Bond energy
It is easier to break the attraction involving ___ bonds as compared to triple bonds
Single
Properties of a Covalent Bond
- Distance between the nuclei of two atoms involved in a covalent bond
- Usually measured in picometers (pm)
Bond length
“For a given pair of atoms, a higher bond order results in a ___ bond length and a ___ bond energy.” (Silberberg, 2013)
Shorter; Higher
Lower or Higher
Covalent compounds, whichever state they are, usually have ___ boiling and melting points compared to ionic compounds
Lower
Covalent or Ionic compounds?
- Do not have freely moving electrons nor do they have ions
- Poor conductors of electricity
Covalent compounds
Involves a metal-metal interaction usually of the same element
Metallic bond
This bond is formed by the delocalized electron cloud surrounding metal ions
Metallic bond
The ability of an atom in a molecule to attract shared electrons
Electronegativity (EN)
4 elements with high EN and usually associated with polar covalent bonds
- Fluorine (F)
- Oxygen (O)
- Nitrogen (N)
- Chlorine (Cl)
Electronegativity difference equal to or greater than this value indicates a polar covalent bond
0.5
Forces existing between molecules
Intermolecular forces of attraction (IFA)
- A charged particle
- Contains an electrical charge
Ion
A molecule with two atoms of opposite charges
Dipole
- Occurs when the partial positive end of a molecule is attracted to the partial negative end of a neighboring molecule
- Occurs when polar molecules come very close to one
another
Dipole interaction
A special type of dipole interaction existing between the hydrogen atom in a polar bond (usually H-F, H-O and H-N) and an unshared electron pair of an electronegative atom
Hydrogen bond
The attraction between an ion to a neighboring polar molecule
Ion-dipole interactions
A polar molecule alters the electron cloud surrounding a nonpolar molecule such that it induces the formation of a
dipole
Induced dipole interaction
Measure of how easily the surrounding electron cloud can be affected and subsequently distorted
Polarizability
- Stands for effective nuclear charge
- Used to describe the net positive charge experienced by an electron in a multi-electron atom
Zeff
Increases or Decreases?
Polarizability ___ down the groups in the periodic table because atomic size increases (more electron shell)
Increases
Increases or Decreases?
Polarizability ___ from left to right across a period in the periodic table because the increasing ___ shrinks atomic size and holds the electrons more tightly
Decreases; Zeff
More or Less?
Cations are ___ polarizable than their parent atoms because they are smaller; anions are ___ polarizable because they are larger
Less; More
The weakest intermolecular forces that occur between molecules that come very close to one another
Van der Waals interactions
Induced dipole interactions and London dispersion forces fall into this category of intermolecular process
Van der Waals interactions
Higher or Lower?
The stronger the intermolecular force of attraction, the ___ the temperature is needed to break the bond and reach the specific boiling point
Higher
Higher or Lower?
If the surface area of interaction is more extended than the other, then ___ freezing point is required
Lower
