1b. Types of chemical bond Flashcards
What is a covalent bond?
A shared pair of electrons
What holds the atoms together when they form covalent bonds?
The common (electrostatic) attraction the nuclei have for the shared pair of electrons.
What is the bonding contiuum?
A measure of how covalent or ionic a bond will be based on electronegativity difference.
What is a “pure” covalent bond?
A bond formed between atoms with identical electronegativity values.
What is a polar-covalent bond?
A bond formed between atoms with an electronegativity difference between 0.5 and 2.0 (approx)
What is the net result of a polar bond in terms of the atoms involved?
One atom will carry a partial +ve charge and the other a partial -ve charge.
What name do we give to the separation of charge in a covalent bond?
A permanent dipole
In a polar bond, which atom carries the partial negative charge?
The atom with the highest electronegativity value
When do ionic bonds form?
When the atoms involved have a very large electronegativity difference.
Which atom will accept the bonding electrons to form a negative ion?
The atom with the highest electronegativity value.
What is meant by “ionic character”
The degree to which a bond will be 100% ionic
What is the trend in ionic character?
What are the properties of covalent molecular bonding?
- low melting points
- do not conduct electricity
- can be solid at room temp but lots are liquids or gases
What are the properties of ionic bonding?
- high melting points
- do not conduct electricity as solids but do as liquids or in solution
- all are solid at room temp
What are the properties of covalent network bonding?
- high melting points
- do not conduct electricity
- all are solid at room temp
