UNIT 1 TOPIC 2 Flashcards
What is covalent bonding?
sharing of electrons between non-metals
What is the Lewis Structure?
digram representing bonding with dots and crosses
What is Structural Formula?
diagram representing bonds with lines
What is the VSEPR theory?
Valence Shell Electron Pair Repulsion
theory that states that electrons pairs repel each other so they will move as far apart as possible, thus creating different shapes
What is polarity?
property of having one partial positive and one partial negative charge
What is a polar molecule?
a molecule that displays polarity and has a partial positive and negative charge
What is a non-polar molecule?
a molecule that has no overall charge
What is the relation between polarity and molecular shape?
Symmetrical molecules tend to be non-polar and asymmetrical molecules tend to be polar
due to equal charges on both sides cancelling each other out
What are the 3 main types of intermolecular bonding?
hydrogen bonding, dipole-dipole attraction and dispersion forces
What is hydrogen bonding?
type of intermolecular bond occurs when hydrogen bonds to nitrogen, oxygen or fluorine (H-NOF) on one molecule, as well as a neighbouring one
What is dipole dipole attraction?
a type of intermolecular bond that occurs when there is a permanent partial charge/polarity
What are dispersion forces?
a type of intermolecular bond that occurs due to electrons always moving, causing temporary dipoles, which attract and bond to other temporary dipoles
What is the difference between intermolecular and intramolecular bonding?
intermolecular is between molecules and intramolecular is between atoms
What are molecular properties often determined by?
intermolecular forces/bonding
What is the correlation between energy and bond strength?
the stronger the intermolecular bond the more energy required to break the bond
What are melting/boiling points?
the temperature in which a solid becomes a liquid or a liquid becomes a gas
How are melting/boiling points related to structure and bonding types?
If the structure and bonding type is stronger and harder to break then the melting/boiling point will be higher as the molecule needs to gather more energy via heating break bonds and change states
What is conductivity?
the ability to allow electric current to flow though
What is needed for conductivity to occur?
free moving electrons, which are not present in solids, thus structure needs to be broken or allow free moving electrons
What is an allotrope?
the different physical form of an element due to different structural atom arrangements
When does polarity increase?
as electronegativty difference increases
What is a diatomic molecule?
molecule with same type of atom
What electronegativity difference is considered non polar?
under 1.7
