Unit 1: Bonding Flashcards
(52 cards)
What are Lewis dot diagrams?
They are representations of how atoms could achieve stable electron arrangements by sharing or transferring electrons.
what are valence electrons?
What are they used for?
electrons in the highest energy level (outermost shell)
They are the only electrons used in a chemical reaction.
What is an orbital?
What do you need to do to get a full orbital?
A region where two electrons may exist.
each orbital can hold two electrons and there are entire four or one orbitals depending on an energy level.
In order to get a full orbital, all other orbitals must have one electron.
for example: if you were trying to create a diagram of aluminum you cannot get a full orbital because you would get an empty orbital.
What is a chemical bond?
electrostatic attraction between 2 particles (ions, atoms, molecules)
what are ionic bonds?
The attraction between negative and positive ions, resulting in the transfer of valence electrons.
(two elements give and take electrons to fill valence shell)
What are covalent bonds?
The simultaneous attraction of nuclei of two atoms to share electrons
(sharing electrons to fill valence shell)
what are single, double, and triple covalent bonds?
It is the different amounts of electrons shared in covalent bonds (shown through the connected lines)
single = two electrons shared
double = four electrons are shared
Triple = six electrons are shared
(all shared electrons are used with the remaining electrons to complete the shell of the non-metals)
What is stereochemestry?
Study of 3D spatial configuration of molecules and how it affects reactions.
What is the VSEPR Theory?
It stands for Valence Shell Electron Pair Repulsion.
The number of electrons surrounding the central atom can predict the stereochemistry of a molecule
Key concept: all pairs of valence electrons repel each other and try to get as far away from each other as possible.
How to draw the different types of diagrams for molecules?
Review NOTES!!!
What happens when two electrons get closer to each other?
They repel.
What are the three different lines used to represent a 3-D shape of a molecule?
Solid line = directly plane
Wedged line = front Z plane
Dashed line = Back Z plane
(Z is front and back, X is left and right)
What does A, X, and E mean in a general formula
A = number of peripheral atoms (almost always one)
X = number of peripheral atoms
E = lone pairs
(the formula made with these variables helps you figure the shape of the atom)
What is the geometry of the formula AX2
Triatomic linear - a straight line
Only uses straight lines
Why can boron bond with six? And beryllium bond with four?
Because their electrons are super close to the nucleus they can bond with fewer atoms
(Only them though)
What is AX3?
Trigonal planar - Y shape
Only straight lines
What is AX4?
Tetrahedral - a Birds-foot shape
has one dashed, one wedged, and two straight lines
What is AX3E?
Trigonal Pyramidal - Pyrimid
(One dashed, one dotted, and one straight).
What is AX2E2?
V- Shaped, Bent, Angular, - Tipi
Two straight lines
What is AXE3?
Diatonic linear - Pair
one straight line
What is Electronegativity?
How can you have higher electronegativity?
The relative ability of an atom to attract bonding pair electrons in valence orbital
More electrons in valence = higher electronegativity
Less energy levels = higher electronegativity
This means nonmetals have higher electronegativity
(Nobel gases do not have electronegativity because of their stability)
What are the characteristics of covalent bonding?
How does the bonds work?
If both atom’s electronegativity is high, the bonding pair is shared
This is then usually two non-metals
The simultaneous attraction of nuclei for a shared pair of bonding electrons
What is metallic bonding?
What are its characteristics?
If both electronegativities are low atoms share electrons as they move freely through the compound (this is why metals are conductive)
creates an attractive force around metal in all directions
Atoms in solid metals may move around each other without moving apart. This creates its malleability and ductility.
(Not ionic compounds because this is TWO metals)
What does the difference of EN give you?
And their difference numbers for each
Larger than 1.7 = Ionic
- 4 - 1.7 = polar covalent
- 4 - 0 = nonpolar covalent
0 or 0.1 between metals = metallic
