Chemistry test 2 Covalent bonds & Molecular Compounds Flashcards
What do groups of atoms held together by covalent bonds called?
Molecules
What is a covalent bond?
A covalent bond is the electrostatic forces of attraction between the positive nuclei and the negative shared electrons in the bonded atoms.
What is meant by a Double Bond?
A double bond is a type of chemical bond in which TWO pairs of electrons are shared instead of one
Properties of simple covalent structures
- Usually gases or liquids at room temperature (if solid,
they are soft solids) - Low melting points and boiling points
- Do not conduct electricity
Why do simple covalent structures have low Melting point and boiling point?
The covalent bonds within these molecules are strong (covalent) but the bonds between molecules weak (intermolecular forces) and easy to break
What is Valency?
Valency is the amount of electrons needed to complete a atoms outer shell
Why are Molecular compounds unable to conduct electricity?
There are no Free electrons due to the strong electrostatic forces between the positive nuclei and the negative electrons keeping them in place.
What is a Monomer?
Small molecules that join together
by covalent bonds
What is a polymer?
A long chain molecule made from many
monomers joining together.
Which has a higher melting/boiling point , Polymer or Monomer? why?
Polymer due to the longer chains which contain more intermolecular forces
Long chains get tangled meaning they will need more energy to be broken
