Chapter 7 Flashcards
What effects the properties of molecules?
Their size and shape.
What type of bonding occurs between non-metals?
Covalent bonding.
What’s involved in covalent bonding?
The sharing of electrons.
What is a single covalent bond?
The sharing of 2 electrons.
What does a double bond involve?
The sharing of 4 electrons.
What does a triple bond involve?
The sharing of 6 electrons.
How many electrons are commonly in an atom’s outer shell?
8
What are the valence electrons not involved in covalent bonding called?
Non-bonding electrons, or lone pairs.
How do bonding and non-bonding pairs position themselves and why?
As far away as possible because they repel each other.
How do double bonds behave?
As one set of negative charge.
What determines the shape of a molecule?
All the electron pairs, although actual shape is determined by the bonding atoms only.
Compare the size of covalent bonding within molecules to bonding between molecules
Bonding between covalent molecules is small compared to bonding within covalent molecules.
What are the 3 main types of intermolecular forces?
Dispersion forces, dipole-dipole attraction and hydrogen bonding.
Which 2 types of intermolecular bonding only occur between polar molecules?
Dipole-dipole and hydrogen bonding.
What makes a molecule polar?
They are polar when they contain polar covalent bonds which are not symmetrically arranged around a central atom.
What bonding is between atoms of different electronegativity?
Polar covalent bonding.
What is electronegativity a measure of?
An element’s ability to attract electrons.
When does hydrogen bonding occur?
When hydrogen is bonded to N, O, F.
What kind of bonding occurs between polar and non-polar molecules?
Hydrogen bonding.
What effects the strength of dispersion forces?
Electrons in a molecule. The more electrons, the greater the dispersion force.
What is a covalent lattice composed of?
Non-metal atoms covalently bonded to each other in 3D.
What are the properties of substances with a covalent network lattice?
High melting points, not conductors of electricity and are hard.
Describe the covalent structure of graphite
Covalent network lattice made up of carbon atoms covalently bonded to each other in 2D, creating layers held together with weaker dispersion forces.
What are the properties of a substance with a covalent network lattice?
High melting point, conducts electricity and is hard in one dimension.
Describe the forces of molecules in covalent molecular substances
Strong covalent bonds within the molecules and weak intermolecular forces between molecules.
What are the properties of covalent molecular substances?
Low melting temperature and boiling temperature, not conductors of electricity, many are gasses or liquids at room temperature.
