[CHEM] Unit 7- Bonding Flashcards
Breaking a bond is ___ (absorbs energy)
Endothermic
Creating a bond is ___ (releases energy)
Exothermic
Bonds create substances that have ___ potential ___ and ___ stability
Lower, energy, increased
The octect rule:
Atoms are most stable with a full valence shell
H, He, and Li have ___ valence electrons
2
Be has ___ valence electrons
4
B has ___ valence electrons
6
T/F: The typical full shell of valence electrons IS NOT 8
F- the typical full shell is 8
Nobles gases generally have a ___ valence shell and are ___
Full, unreactive
T/F: Kr and ___ can bond with F
T- Kr and Xe can bond with F
Metals have ___ valence electrons and low ___
Few, ionization energy
The nucleus and ___ electrons (referred to as the “kernels”) form a crystal ___
Inner, lattice structure
Ionic bonds, or electrovalent bonds, are a ___ bonded to a ___
Metal, nonmetal
Ionic bonds generally have a electronegativity of ___ or more
1.7
The solid of an ionic bond is a ___
Hard crystal lattice
Ionic bonds have ___ melting and boiling points- generally in the ___
High, thousands
Ionic bonds can only conduct electricity when ___ or ___
Liquid, aqueous
Ionic bonds generally ___ in water
Dissolve
The ___ difference in electronegativities, the ___ ionic the bond is
Greater, more
The ___ pulls valence electrons ___ from the ___, making positive and negative ions which ___
Nonmetal, away, metal, attract
Covalent bonds are:
Two nonmetals that bond; they share electrons
Covalent bonds have an electronegativity that is ___ than 1.7
Less
T/F: Covalent bonds CANNOT include atoms of the same element
F: they can
T/F: Polyatomic ions are covalent
T
T/F: Covalent bonds CANNOT exist in all three states of matter, and have HIGH boiling and melting points
F: They can exist in all three states, and have LOW melting and boiling points
Covalent bonds are ___ and ___ conductors of electricity
Brittle, poor
Nonpolar bonds are 2 atoms of the ___ element that share the valence electrons ___
SAME, EQUALLY
Polar bonds are 2 atoms of ___ element(s) that share the valence electrons ___
DIFFERENT, UNEQUALLY
MEMORIZE: Which elements have the highest electronegativities- in this specific order?
F,O,N,Cl
Polar covalent bonds have electronegativities ___ than 1.7
Lower, smaller, less
Ionic bonds have electronegativities ___ than 1.7
GREATER
SNAP:
Symmetrical Nonpolar Asymmetrical Polar
___ bonds are the easiest to break
Single
___ bonds have the most bond energy
Triple
A single bond is one ___ bond
Sigma
A double bond is one ___ bond and one ___ bond
Sigma, pi
A triple bond is one ___ bond and two ___ bonds
Sigma, pi
A coordinate covalent bond is defined as:
Where both shared atoms come from the same source; ex: NH4+1 because N has five electrons and the two unpaired left over would go to the last H
The general trend for hybridization is:
The hybridization is just sp_ whatever is one less than the number of bonding domains
EVERYTHING IS ABOUT THE ___
CENTER ATOM
Allotropes are:
2 forms of the same element but bonded differently, resulting in different physical and chemical purposes
Network bonds/solids are:
A special case of covalent bonds which have very high melting points and are hard. The atoms are bonded by covalent bonds in a continuous network extending throughout the material. There are no individual molecules.
Network bonds exist in a ___ ___ in which all of the atoms are bonded together ___
Crystal lattice, covalently
Solubility rule:
“Like dissolves like”- for example, water and oil do not mix because water is polar and oil is nonpolar
Polar solvents only dissolve ___ and ___ solvents because they ___ have charged parts
Ionic, polar, DO
Nonpolar solvents only dissolve ___ solvents because they ___ have charged parts
Nonpolar, DO NOT
T/F: Hydrogen bonding is the weakest of all IMFs (intermolecular forces) and has a low boiling point and low surface tension
F: This is false. Hydrogen bonds are the strongest of IMFs and have high boiling points and surface tension
Hydrogen bonding only works when __, ___, or ___ bond with ___
F,O,N, H
Dipole-dipole forces are between 2 ___ molecules and are ___ than hydrogen bonding
POLAR, weaker
T/F: Van der Waals forces are the strongest of the IMFs
F: VdW forces are the WEAKEST
Van der Waals forces are between ONLY ___ molecules or ___ ___
Nonpolar, noble gases
VdW forces are created because:
Electrons move, creating temporary charges that attract molecules for short periods of time
___ molecules lead to stronger VdW forces
Larger (heavier mass)
