Chemical Bonding Flashcards
In n=1, a full octet consists of how many electrons?
2
Created when a metallic cation forms an electrostatic bond with a non-metal anion
Ionic compound
Metals are ________
Cations
Non-metals are _________
Anions
Cations ________ electrons
Lose
Anions _________ electrons
Gain
These elements lose electrons from their highest s-sublevel first before losing from their d-sublevel
D-block cations
How strong are ionic bonds?
Very strong
Since it ionic bonds are very strong, a lot of energy had to be put in to break them apart. This makes them very ___________
Endothermic
In ionic solids, a higher energy correlates with a _________ melting point
Higher
The energy required to keep a bond together is ________ to the energy required to break a bond apart
Energy
The smaller the ion, the ____________ the melting point
Higher
The larger the ion, the __________ the bond
Weaker
Ionic solids generally have ______ melting points
High
Are ionic solids typically very soft or hard?
Hard
How well do ionic solids evaporate?
Not well
Ionic solids are not malleable or ductile and _________ along planes
Cleave
Most ionic solids are _______ in polar solvents
Soluble
Ionic solids conduct electricity only when molten or ____________ in a polar solvent
Dissolved
The higher the concentration of ions in a solution, the ________ the electrical conductivity
Higher
A bond in which one atom shares one or more pairs of electrons with another atom so that they both acquire full octets
Covalent bonds
___________ are not transferred in covalent bonds
Electrons
Covalent bonds occurs between two ____________
Non-metals
As two atoms get closer to each other, the attraction between the __________ of one atom and the ________________ of the other atom increases
Nucleus, valence electrons
An elements ability to attract electrons in a chemical bond
Electronegativity
Electrons spend more time around an atom with a ________ electronegativity
High
What type of bond does a compound with an electronegativity difference of less than 0.5 have?
Nonpolar covalent bond
What type of bond does a compound with an electronegativity difference of 0.5-1.9 have?
Polar covalent bond
What type of bond does a compound with an electronegativity difference of more than 1.9 have?
Ionic bond
In polar covalent bonds, the atom with the higher higher electronegativity develops a ________________ as the valence electrons from both atoms spend more time around it
Partial negative charge
In polar covalent bonds the atom with the lower electronegativity develops a ___________________ which is equal in magnitude to the partial negative charge of the more electronegative atom
Partial positive
_____________ increase as electronegativity differences increase
Partial charges
The sum of the partial charges in any molecule or ion is always equal to the ________________ of the species
Overall
Two or more non-metals bonded together to form a compound
Molecules
Lewis structures are only used for _____________
Covalent compounds (molecules)
When making Lewis structures, the __________ electronegative atom should go in the center
Least
Hydrogen is always a __________ atom
Terminal
Beryllium and boron are examples of ______________ atoms
Electron deficient
Atoms in periods __________ can bond with other atoms in such a way that they end up with more than 8 electrons in their octets
3-7
How are expanded octets possible?
They have d-orbitals in their outer shells that can accept electrons
The more likely Lewis structure will have formal charges that are closer to or equal to ________
Zero
Negative formal charges should reside on the more __________ elements in the structure
Electronegative
How do you calculate formal charge?
(# of valence electrons assigned to the neutral atom) - (# of atoms assigned to the electron in the atomic structure)
The potential energy of valence electrons _____________ as they approach the nucleus of another atom
Decreases
Energy is _________ during the formation of a bond
Released
The more energy released during the formation of a bond the ________ the bond will be
Stronger
The amount of energy that is required to break the bond between two specific atoms in a molecule
Bond energy
As the atomic radii of bonding atoms increase, the bond length ___________
Increases
As the number of bonds between two atoms increases, the bond length __________
Decreases
Why does the number of bonds between atoms correlate with the bond length?
As the electron density between the atoms increases, the attractive forces between the protons and valence electrons increases
How do you find bond order?
of bonds/ # of terminal atoms
A higher bond order correlates with a __________ bond length
Shorter
Higher bond order correlates with a __________ bond energy
Higher
How many bonds does carbon have?
4
How many bonds does nitrogen have?
3
How many bonds does oxygen have?
2
How many bonds do fluorine, chlorine, bromine, iodine, and hydrogen have?
1
Elements tend to gain or lose electrons to acquire a full _________
Octet
What does VSEPR theory stand for?
Valence Shell Electron Pair Repulsion Theory
Charge clouds repel each other do to _____________________
Coulombic repulsion
____________ move as far away from each other as possible
Terminal atoms
Theory that states that bonding occurs when atomic orbitals overlap
Valence bond theory
What is the problem with valence bond theory?
It gets the bond angle wrong
What is the solution to valence bond theory?
Hybrid orbitals
____ bonds have side to side overlap
Pi
________ bonds have head to head overlap
Sigma
Single bonds are ______ ponds
Sigma
How many pi and sigma bonds does a double bond have?
1 pi, 1 sigma
How many pi and sigma bonds does a triple bond have?
2 pi, 1 sigma
What type of bonds are able to spin on an axis?
Single bonds
Why can’t double bonds spin?
Pi bonds are rigid and prevents the sigma bonds from spinning, locking the molecule in place
What are isomers?
Molecules with similar formulas but different shapes
Why do pi bonds cause isomers?
They creat a lack of flexibility in the molecule
Type of isomer where the carbon chain follows the same side
Cis
Type of isomer where the carbon chain follows opposite sides
Trans
What type of bond is shorter?
Sigma
A molecule is polar when the molecule has a _____________ moment
Dipole
The normal configuration of the electron about the atom or ion of an element
Ground state
At the ground state, electrons are at their ________ possible energy level
Lowest
When particles absorb energy (ex. heat) they leave their ground state and become __________
Excited
Excited state is ______
Unstable
As electrons return to their ground state, they release the absorbed energy in the form of _____________
Electromagnetic energy
A red color light possesses ______ energy
Low
Violet possesses _________ energy
High
Metallic ions possess electrons that are _________ excited
Easily
