Covalent Bonding Flashcards
What is the name of a covalent substance
Covalent molecular substance
What do covalent bonds create
Molecules
What is a covalent molecular element
Identical atoms forming a covalent bond
What are discrete molecules
When each molecule is separate or distinct of another
What are monatomic and diatomic molecules
Monatomic are molecules are made by one atom of a element and are the noble gases
Diatomic are molecules that have two of the same element in a molecule and each having a full valence shell
Do non metals have high or low electronegativity
High
What is the atom called with the most covalent bonds
The central atom
Explain a double or triple bond
When atoms share two or more electrons each
What does the VSEPR theory state
That lone pairs in the molecule repel each other and take a position as far away as possible from one another
What is a non polar bond
When atoms in a molecule have the same electronegativities they share the electrons equally and are evenly distributed.
What is a polar covalent molecule
When one atom within a molecule has a higher electronegativity therefore it pulls the shared electrons closer to its nucleus and therefore has a slight negative charge and the other has a slight positive charge
What is a dipole
When in a molecule there is a positive and negative charge separation, that is a polar molecule
What is a molecular dipole or a dipolar molecule
When a covalent molecule is polar, one side is positive and the other negative.
What are the rules for determining the polarity of a molecule
- Draw the proper structural diagram of the molecule
- Identify the electronegativity of all atoms
- Use the shape to determine if the molecule is polar. If bond dipoles cancel each other out then it is non polar (in opposite directions)
In general what shape molecules are polar and not polar
Non-POLAR: linear, planar and tetrahedral
POLAR: v-shaped or Pyramidal
What is the difference between intermolecular force and intramolecular forces
Intermolecular: the forces between molecules of a substance
Intramolecular: the forces inside a molecule
What does intermolecular forces usually determine
Whether the compound exist in solid liquid or gas state
From weakest to strongest list the intermolecular forces
Dispersion forces
Dipole-dipole interactions
Hydrogen bonding
Explain dispersion forces
This occurs when the nuclei of atoms in one molecule are able to attract the electrons of neighbouring molecules. All covalent molecules have dispersion forces
What determines the strength of a dispersion force
The amount of electrons, more = stronger
What is an instantaneous dipole
Due to the electrons moving so fast around the molecule, at any point in time there is a high chance that most electrons of that molecule are found in one side of the molecule. This can cause a shift in neighbouring molecules and therefore create a weak dipole bond
Explain Dipole-dipole interactions
This occurs when molecules are polar. The positive side of one molecule is attracted to the negative side of another and vise versa. Thus all the molecules in the sample are being attracted this force. This results in a higher boiling point and is more likely to occur as a solid or liquid in room temp
Explain hydrogen bonding
When hydrogen bonds to a higher electronegative atom its electon moves closer to said atom leaving hydrogen un shielded. The other molecule can be a lot closer to the hydrogen atom and causes a very strong bond. Each atom has to be bonded with hydrogen
What elements can only create hydrogen bonding
Fluorine, oxygen, nitrogen
