3.1.3.2 Nature of Covalent and Dative Covalent Bonds Flashcards
What is dative covalent bonding?
When both of the shared electrons come from the same atom
What are the properties of small covalent bonds?
Low melting/boiling points
Don’t conduct electricity
Are electrical insulators
Small covalent molecules that are polar or can form hydrogen bonds are soluble
What are the properties of giant covalent bonds?
Extremely high melting/boiling points
Electrical insulators
Don’t conduct electricity
Aren’t soluble in water
What are covalent bonds?
Where atoms share electrons to have a noble gas arrangement
Formed between a pair of non-metal atoms
What is a molecule?
A small group of covalently bonded atoms
How does a covalent bond work?
The atoms are held together by the electrostatic attraction between the nuclei and shared electrons
How do you represent two shared electrons in a covalent bond?
By a double line
Why do covalent bonds have low melting/boiling points?
The inter-molecular forces are weak even though covalent bonds are strong
Do covalent bonds conduct electricity?
No, they’re neutral molecules and there are no charged particles to carry the current so they’re poor conductors
Which atom accepts two electrons in a dative covalent bond?
The atom that doesn’t have a full outer shell (electron-deficient)
Which atom donates two electrons in a dative covalent bond?
The atom that is donating electrons has a pair of electrons that isn’t being used
Called a lone pair
How do you express a dative covalent bond?
With an arrow that points towards the atom accepting the pair
Why is it hard to break a covalent bond?
You have to put in energy to overcome the attraction in order to form a covalent bond
How do you work out the charge of a covalent bond?
Protons minus electrons
What are the types of bond in a double bond?
Sigma bond: between the nuclei of the two atoms
Pi bond: second pair of electrons
