Physical - 1.3 Bonding Flashcards
Define coordinate bond
A coordinate (dative covalent) bond contains a shared pair of electrons with both electrons supplied by one atom.
Define covalent bond
A shared pair of electrons between two non-metals.
Define dipole
Difference in charge between the two atoms of a covalent bond caused by shift in electron density in the bond due to the electronegativity difference between elements participating in bonding
Define electron pair repulsion
Repulsion that exists between electron repairs due to negatively charged electrons.
Repulsion means electron pairs position themselves as far apart from each other as possible around the central metal at
Define electronegativity
The power of an atom to attract the electron density in a covalent bond towards itself
Define electrostatic forces
The strong forces of attraction between oppositely charged ions
Define hydrogen bonding
An interaction between a hydrogen atom and an electronegative atom, commonly nitrogen, fluorine or oxygen. The slightly positive hydrogen is attracted to the lone pair on the electronegative atom. Hydrogen bonds are stronger than van der waals and dipole dipole forces but weaker than ionic and covalent bonds.
Define intermolecular forces
The forces which exist between molecules. The strength of the intermolecular forces impact physical properties like boiling and melting point.
Define ion
An atom molecule with an electric charge due to the loss or gain of electrons
Define ionic bond
A metal atom loses electrons to form a positively charged ion and a non-metal atom gains these electrons to form a negatively charged ion. An ionic bond is formed between charged ions.
Define ionic compound
Chemical compound formed of ions, held together strong acid forces.
Define lattice structure
Repeating regular arrangement of atom/ion/molecules. This arrangement occurs in crystal structures.
Define macromolecular crystal structure
Giant covalent structures. Macro molecules have very high melting points because many strong covalent bonds have to be broken. Examples include diamond and graphite.
Define metallic bond
The bond present in metals between the positive metal ions and negative recharge electrons
Define permanent dipole dipole forces
When molecules with polar covalent bonds interact with dipoles in other molecules dipole dipole intermolecular forces are produced between the molecules. These intermolecular forces are generally stronger than van der waals forces but weaker than hydrogen bonding.
Define polar bond
Covalent bond between two atoms in which the electrons in the bond are evenly distributed. This causes a slight difference, inducing a dipole in the molecule.
Define simple molecular crystal structure
Structures in which the atoms are joined by strong covalent bonds. Weak intermolecular forces mean simple molecules have low melting and boiling points.
