Bonding AS Flashcards
When are ions more stable
When they are they are closer to oppositely charged ions.
What is the strength of attraction between oppositely charged particles based on
Distance between particles (shorter distance =stronger attraction therefore stronger IB)
Distance also relate to the size of the ions radius (smaller the radius the shorter the distance between ions and stronger attraction therefore stronger IB)
Size of charge each particle has (Greater charge = stronger attraction - stronger IB)
groups of ions arrange themselves to
To minimise distance between opposite charges (maximise attraction)
Maximise distance between like charges (minimise repulsion)
How are ions arranged
They are arranged in a 3D lattice structure (called giant ionic lattice)
Why do ionic compounds have a high melting point
Large amounts of energy are needed to break lattice apart
How is a covalent bond formed
The positively charged nuclei will be attracted to the increase in electron density between the atoms pulling them inward and closer together.
Orbitals overlap / merge forming a new orbital called bonding/ molecular orbital
He electrons can exist anywhere within the new orbital
Both atoms have “access” to electrons in this orbital
So they can achieve a full outer shell
What is the distance between 2 nuclei called
Bond length
Definition of a covalent bond
Attraction of a positively charged nucleus to a shared pair of electrons
Why are double bonds stronger than single bonds
Due to the different shapes and directions of p orbitals . (BUT the second bond (pi) isn’t as strong as the first bond (sigma) therefore meaning a double bond isn’t twice as strong as a single bond.
Have both types of bond sigma and pi.
What is a sigma bond
When orbitals overlap easily and and directly
Why is a sigma bond very strong
The nuclei both have high level of attraction to the electrons in the orbital making the sigma bond strong.
What are double bonds always
What are single bonds always
Double bonds = pi bonds (also have sigma bonds)
Single bonds = sigma bonds
Why are pi bonds weaker that sigma bonds
P orbitals bend sideways creating 2 areas of electron density above and below sigma bond. Electrons in this orbital are further from the nucleus therefore meaning less attraction and weaker bond.
What is meant by the term lone pair
Refers to electron pair in the outer orbital of an atom that isn’t involved in bonding .
What is a coordinate/ dative covalent bond
a covalent bond (a shared pair of electrons) in which both electrons come from the same atom.
