Bonding Flashcards
Metallic- what allows a charge to run through metallic structures?
Delocalised electrons
What force holds the structure together?
Electrostatic attraction
What are the physical attributes of metallically bonded compounds?
Can conduct electricity, high boiling and melting points, are malleable and ductile
What allows for malleability in metallically bonded compounds?
Uniform arrangement- in a lattice, all the ions are the same size
Ionic- What do ionic bonds exist between?
Metals and non-metals
What is the direction of electron donation in ionic bonding?
From metal to non-metal
When can an ionically bonded compound conduct electricity?
Aqueous state (electrons will be free to move)
Why is the boiling point in ionic bonding high?
The electrostatic attraction between the positive and negative ions is strong thus to overcome this bond a lot of energy will be required
Why are ionic compounds brittle?
When bonds are moved they repel each other.
What is the chemical process used around ionic bonding?
Electrolysis
Covalent- what is a dative covalent bond between?
An electron deficient molecule and an electron rich molecule
What is covalent bonding?
Shared pair of electrons between two atoms
What is electronegativity?
The ability of an element to attract electron density towards itself in a covalent bond
What is the trend of electronegativity in periodic table?
Increases up a period and across a group
Why are Helium and Hydrogen not electronegative?
They do not form covalent bonds
What is a Van der Waals force?
The forces between oppositely charged atoms
What causes the difference in charge in atoms?
Unequal distribution of electrons in an atom- temporary dipole
What causes induced dipoles in atoms?
When another atom with a temporary dipole approaches another atom causing equal charges to repel.
What factors effect the induction of a dipole?
Number of electrons and size/mass of the atom, how close the atoms can get together (branching)
when do dipole-dipole forces exist?
When there is a permeant dipole present
What do dipole-dipole forces require to exist?
Permanently electronegative elements to create a charge difference
What does hydrogen bonding occur between?
Hydrogen, N/O/F
What is hydrogen bonding?
When a free pair of electron are attracted towards a d+ hydrogen
What is the difference between the densities of water and ice? Why?
Ice is less dense than water due to the H bonds increase in length so to keep the waters bond angles the same.
