bonds Flashcards
what are covalent bonds between
nonmetal and nonmetal
how are covalent bonds formed
through sharing electrons
how are ionic bonds formed
through transferring electrons
what are ionic bonds between
nonmetal and metal
what is a polar covalent bond
a bod where one end gets more electrons than the other
which side of a polar covalent bond is negatively charged
the side with more electrons (greater electron density)
which side of a polar covalent bond is positively charged
the side with less electrons
what is electronegativity
the ability of an atom to attract bonding electrons to itself
what happens to electronegativity as you go across the period
it increases
what happens to electronegativity as you go down the group
it decreases
what is a pure covalent
where the difference in electronegativity between bonded atoms is 0; there is equal sharing of atoms
what type of bond is it if electronegativity difference is between 0.1 - 0.4
nonpolar covalent
what type of bond is it if electronegativity difference is between 0.5 - 1.9
polar covalent
what type of bond is it if electronegativity difference is at least 2.0
ionic
what type of bond is it if electronegativity difference is = 0
pure covalent
how to find polarity of bond
look at how far the elements in the bond are from each other on periodic table; if they are further from each other, they will have a greater electronegativity difference and will be more polar
if elements in a bond are far away from each other on periodic table; what is their polarity
increased polarity; increased electronegativity difference
if elements in a bond are close to each other on periodic table; what is their polarity
less polarity; less electronegativity difference
what are bonding pairs
Electrons that are shared by atoms
what are lone pairs
electrons that are not shared by atoms, but rather belong to only one of the particular atoms
what is a single covalent bond
When two atoms share one pair of electrons
what is a double covalent bond
When two atoms share two pairs of electrons
what is a triple covalent bond
When two atoms share three pairs of electrons
polar bond definition
two different elements with significant electronegativity difference between them
What is a resonance structure
a set of two or more Lewis Structures that collectively describe the electronic bonding of a single polyatomic species including fractional bonds and fractional charges
can resonance structures have different numbers of electrons?
No
What do better resonance structures have?
fewer formal charges; smaller formal charges; negative formal charge on the more electronegative atom
what must formal charge of an ion add up to
the charge of the ion
what must the formal charge of a neutrally charged molecule add up to
zero
what is formula to find formal charge
(# of valence electrons) - [ (# of nonbonding electrons) + (½ x # of bonding electrons) ]
what happens to bond strength as you go down a column
the bonds get weaker
what happens to bond strength as you go across the period
the bonds get stronger
the shorter the covalent bond, the _______ the bond
stronger
the more electrons two atoms share, the _________ the covalent bond
stronger
how is bond strength measured
bond strength is measured by how much energy must be added into the bond to break it in half
how is bond length measured
Bond length is determined by measuring the distance between the nuclei of bonded atoms
