Chemistry Ch. 6
what is apparent charge on the chlorine atom in the molecule HCl
+1
bond energy is the energy
change as atoms get closer together
the fact that metals are malleable and ionic crystals are brittle is best explained in terms of their
chemical bonds
dipole
created by equal but opposite charges that are separated by a short distance
if two covalently bonded atoms move closer than a distance of the bond length, the PE of the atoms
decreases
in general as you move from RIGHT to LEFT across any row of the periodic table, the strength of a metallic bond
decreases
you can estimate the degree to which a bond between two atoms is ionic or covalent by calculating
difference in the atoms' electronegativities
chemical bonding in metals is
different from ionic or covalent bonding
amount of energy required to boil a liquid is
directly related to the energy required to break the inter molecular bonds -bond break when going into gas into individual atoms from liquid form
the measure of an atom's ability to attract electrons is its
electronegativity
ionic bond
electrostatic attraction between anions and cations ex: Na-Cl
type of energy that is a measure of strength for a metallic bond
enthalpy of vaporization
compared with solid ionic compounds, solid molecular compounds generally
have lower melting points
atoms with a strong attraction for electrons they share with another atom exhibit
high electronegativity
in general, the strength of the metallic bond___ moving from left to right on any row of the periodic table
increases
the greater the electronegativity difference between two atoms bonded together the greater the bond's percentage of
ionic character
how to find a pair of elements that will most likely have the GREATEST ionic character
largest subtract smallest (3.0 - .8 = 2.2
type of energy that is a measure of strength for an ionic bond
lattice energy
which of the following is the result of visible light absorbed by a metal
light at frequency similar to the absorbed frequency is emitted
the shape of molecules that contain ONLY 2 atoms is
linear, 180
which are the intermolecular forces that can act between non-polar molecules
london dispersion forces
compared with the neutral atoms involved in the formation of an ionic compound, the crystal lattice that results in
lower PE
mobile electrons in the metallic bond are responsible for
luster, thermal conductivity, and electrical conductivity
the valence electrons in a metallic bond
move freely throughout the network of metal atoms
atoms that are bonded with an electronegativity difference of 0-0.3 are generally considered to be
nonpolar-covalent compounds
a chemical bond between atoms results from the attraction between the valence electrons and ____ of different atoms
nuclei
within a metal, the vacant orbitals in the atoms' outer energy levels
overlap
the VSEPR theory
predicts the shape of some molecules and assumes that pairs of valence electrons surrounding an atom repel each other
when an atom completely gives up its valence electrons to another atoms, they form a bond considered to be
purely ionic (atom that gives up valence electrons becomes a cation, the atom that gains the electrons becomes an anion, thus there is an ionic attraction between the two)
In metals, the valence electrons are considered to be
shared by all surrounding atoms
how to find a pair of elements that will most likely have the LEAST ionic character
take the two biggest, and subtract (3.5-3.0=.5)
which of these is responsible for the good electrical conductivity of metals
the ability of electrons to move freely about the crystal structure
nonpolar covalent bond
the electrons between two bonded atoms is equal, 0-0.3 -ex: H-H
polar covalent bond
the electrons between two bonded atoms is unequal, one atom is pulling harder on the atom that the other, hogging -ex: H-O-H
In a crystal of sodium chloride, how many oppositely-charged ions does each Na- and Cl- ion have clustered around it
6
a covalent bond consists of
a shared electron pair
as light strikes the surface of a metal, the electrons in the electron sea
absorb and re-emit light
in a crystal of an ionic compound, each cation is surrounded by a # of
anions (in order to be neutral)
atoms seldom exist as independent particles in nature because
atoms are more stable when they combine with other atoms
the lewis structure of which of the following compounds does not follow the octet rule
BF3
Strongest to weakest bonds
Covalent Ionic metallic Hydrogen dipole-dipole induced dipole London Dispersion
non polar covalent bond (EN)
EN= 0 -.3
polar covalent bond (EN)
EN= 0.3 - 1.7
Ionic bond (EN)
EN= > 1.7
dipole-dipole forces
attraction between polar molecules -like magnets -ex:I-Cl I-Cl ^ attraction between the S- and S+ sides
type of energy that is a measure of strength for a covalent bond
bond energy
to draw a lewis structure, it is not necessary to know
the length of the bonds
bond length between two bonded atoms is
the separation at which their PE is minimum
what is the relationship between the enthalpy of vaporization of a metal and the strength of the bonds that hold the metal together
the stronger the bond, the higher the heat/ energy required to vaporize the metal.
a single covalent bond involves the sharing of
two electrons
induced dipole
when a nonpolar molecule and polar molecule come together, the nonpolar molecule becomes polar for a bit
