A1: Shapes and IMFs Flashcards
Linear Shape
2 bonded regions, 0 lone pairs, 180
Trigonal Planar shape
3 bonded regions, 0 lone pairs, 120
Why is ice less dense than water?
Hydrogen bonds hold water molecules in ice further apart in an open lattice structure, so ice is less dense
Why is water a liquid as room temperature? (and has a relatively high melting and boiling point
Hydrogen bonds are much stronger than London forces, so more energy is needed to overcome them
Define dipole
Separation of charge so that one atom of a polar bond or molecule has a delta positive charge and one has a delta negative charge
Simple molecular bonding
when solid has a regular structure called a simple molecular lattice.
Molecules held together by weak intermolecular forces , atoms within molecules held together by strong covalent bonds.
Melting and boiling points of simple molecular substances
Covalent bonds aren’t broken when melted.
Low MP and BP as the weak intermolecular forces between molecules can be overcome by little energy.
Electrical conductivity of simple molecular substances
They are non conductors as they have no mobile charge carriers.
Octahedral shape
6 bonded regions, 0 lone pairs, 90
Non Linear shape
2 bonded pairs, 2 lone pairs, 104.5
Tetrahedral shape
4 bonded regions, 0 lone pairs, 109.5
Pyramidal shape
3 bonded regions, 0 lone pairs, 107
Define electronegativity
The ability of an toms to attract the bonding electrons in a covalent bond
Electronegativity patterns in the periodic table
Electronegativity increases up and across the periodic table
Nitrogen, oxygen and fluorine most electronegative atoms
When is a bond polar?
When there is a difference in electronegativity
