2.5 Flashcards
(39 cards)
What is the primary focus of the Lewis Theory of Bonding?
Atoms bond by sharing valence electrons, forming covalent bonds.
Developed by Gilbert Lewis in 1916.
What is the Octet Rule?
Atoms and ions are stable if they have a noble gas-like electron structure (i.e., a stable octet of electrons).
This rule is fundamental in understanding chemical bonding.
How are electrons most stable according to the Lewis Theory?
Electrons are most stable when they are paired.
This stability is crucial for the formation of bonds.
What happens when atoms form chemical bonds?
Atoms form chemical bonds to achieve a stable octet of electrons.
This is a driving force behind chemical reactions.
How can a stable octet be achieved?
A stable octet may be achieved by:
* An exchange of valence electrons between metal and non-metal atoms
* A sharing of valence electrons between non-metal atoms, resulting in a covalent bond.
These processes underpin the formation of different types of chemical bonds.
What defines ionic bonding?
Ionic bonding is a type of bond where one atom, usually a metal, gives up one or more electrons to a more electronegative atom, followed by electrostatic attraction.
This results in the formation of ions.
What characterizes covalent bonding?
Covalent bonding is characterized by the sharing of electrons between two atoms in a bond.
This type of bond is prevalent among non-metal atoms.
What are Lewis Structures?
Lewis Structures are illustrations that show the sharing of valence electrons in molecules, where lone valence electrons are represented as dots and bonding electron pairs as lines.
Core electrons are not shown in these structures.
How can you determine the number of valence electrons for an element?
The last digit of the number at the top of each column on the Periodic Table indicates the number of valence electrons each element has.
For example, Oxygen in group 16 has 6 valence electrons.
True or False: The Lewis Theory of Bonding only applies to metals.
False.
The theory applies to both metals and non-metals.
Fill in the blank: Lewis suggested that atoms bond by sharing _______.
valence electrons.
This is foundational to the concept of covalent bonding.
What is the first step in drawing Lewis Structures according to the Need-have Method?
Identify the central atom with the highest bonding capacity
The central atom is surrounded by other atoms.
How do you calculate the total number of valence electrons for a molecule?
Add up the number of valence electrons for each atom
For example, in CH4, C has 4 v.e. and each H has 1 v.e., totaling 8 v.e.
What does the Helpful 8 Rule indicate about lone pairs on the central atom?
If the total number of valence electrons is divisible by 8, there are no lone pairs on the central atom
This rule does not apply if H atoms are attached.
What is the fifth step in the Need-have Method for drawing Lewis Structures?
Check if the central atom has 8 electrons; if not, add an extra bond
Each bond contributes 2 electrons.
What should you do with the remaining electrons after placing bonds in Lewis Structures?
Distribute them around the surrounding atoms to ensure each has 8 valence electrons
Any leftover electrons should be added to the central atom.
What is the bonding capacity of hydrogen in covalent bonds?
H can make 1 covalent bond
This is unlike other non-metals which can make more based on their valence electrons.
How many covalent bonds can carbon make?
C can make 4 covalent bonds
This is calculated as 8 - 4 = 4.
What is the significance of atoms in period 3 or greater regarding valence electrons?
They can have more than 8 valence electrons due to expanded octets
This occurs through bonds and lone pairs.
What is the overall charge of a group of atoms in a molecule with no charge?
The overall charge is zero
This applies to neutral molecules.
What is a polyatomic ion?
A group of atoms covalently bonded together with a nonzero overall charge
Examples include sulfate (SO4^2-) and ammonium (NH4+).
Fill in the blank: The central atom in a Lewis structure is the one with the highest _______.
bonding capacity
What is the first step in drawing the Lewis structures of polyatomic ions?
Follow the same steps as in regular Lewis structures, adjusting for charge
