Bonds & Details Flashcards
Covalent bond
When the electrons are not shared equally, it is called?
Electrons shared between 2 atoms
The bond is considered polar
Ionic bond?
Why does the bond stay together?
Electrons are taken and given away, resulting in charged particles.
Bond stays together due to electrical attraction
Covalent bonds result in what shapes?
Ionic bonds?
Covalent- VSEPR shapes
Ionic- crystals
Are acids an ionic or covalent bond?
What does the hydrogen act like?
Ionic
Like a cation
Cation vs anion
Cation- the positively charged ion
Anion- the negatively charged ion
What do covalent bonds form, while ionic bonds do not?
Molecules
Valence electron
An electron in the outermost energy level of an atom that can participate in bonding
Unshared pair (lone pair)
A nonbonding pair of electrons in the valence shell of an atom.
Single bond
A bond in which two atoms share one pair of electrons
Triple bond
Covalent bond in which 2 atoms share 3 pairs of electrons
Double bond
Covalent bond in which 2 atoms share 2 pairs of electrons
Resonance structure
Possible Lewis structure of a molecule for which more than one Lewis structure an be written
Lewis structure
A structure in which atomic symbols represent nuclei and inner-shell electrons and in which dots are used to represent valence electrons
What does VSEPR theory predict?
The 3-D formation of a molecule, shape of the molecule
The shape of molecules that contain only 2 atoms is
linear
Why is there not resonance structures of CO despite its triple bond?
There is no other way of making a different structure
Electronegativity
Tendency of an atom in a molecule to attract shared electrons to itself
How good an atom is at attracting electrons to its nucleus
Is “polar ionic” possible? Why or why not
No, Because in order to be polar, the en has to be less than 2 and greater than .5. If a bond is ionic, it will have an electronegativity greater than 2 meaning that it will never be polar.
When should you use electronegativity to calculate whether or not a bond is polar?
When it is a covalent bond
What does VSEPR stand for?
valence shell electron pair repulsion
Why are nonpolar covalent bonds not common?
Because one atom usually attracts electrons more strongly than the other
Nonpolar covalent bond
Attraction between two atoms in which bonding electrons are shared equally between the atoms
Polar covalent bond
Attraction between two atoms in which bonding electrons are localized on the more electronegative atom
Where on the periodic table is electronegativity the highest?
Upper right hand side
Where on the periodic table is electronegativity the lowest?
Bottom left hand side
Dipole molecule
One that has a partial positive charge at one end and a partial negative charge at the opposite end
In general, if the difference in electronegativity between 2 atoms is between 0 & .4 the bond formed is…
Non polar covalent
If the difference in electronegativity between 2 atoms is between .4 and 2 the bond formed is…
Polar covalent
If the electronegativity difference between 2 atoms is greater than 2 the bond formed is…
Ionic
If one atom has more electronegativity, then it is partially ____
Negative
The positive atoms shown in dipole moment arrows go where?
Towards the partially negative atom because it has more electronegativity
What is meant by unequal sharing of electrons in a polar bond?
More electronegative atoms pull on shared electrons more than the other atom so the charge is not evenly distributed -> opposite sides -> opposite charges
If their are lone pairs on the center element of the covalent bond, is it a polar or nonpolar molecule?
Polar
No lone pairs. Polar or nonpolar molecule?
Nonpolar
If dipole moments cancel out, is the molecule polar or nonpolar?
Nonpolar
If the dipole moments don’t cancel & there are lone pairs, the molecule is…
Polar
Right on the periodic table, what happens?
Nucleus gets bigger so it’s easier to steal electrons (more en)
Down on the periodic table, what happens?
Further away from the nucleus, more energy levels (less en)
Molecules have a certain ____ based on how the electrons repel each other
Shape
