Chapter 2 - Bonding, Structures and Nanoparticles Flashcards
What group of atoms are found naturally unbonded ?
The noble gases
Why are the noble gases unreactive ?
Because they have a full outer shell of electrons which is very stable
What compounds are found in ionic bonding ?
a Metal and a non-metal
What happens in an ionic bond ?
- electrons move from the metal to the non-metal
- each ion has filled a full outer shell
What is the definition of an ionic bond ?
An ionic bond is the attraction between oppositely charged ions.
What is the definition of a covalent bond ?
A covalent bond is a shared pair of electrons
What is the definition of a molecule ?
A molecule is two or more atoms covalently bonded together
What is the definition of diatomic ?
Diatomic means that there are two atoms covalently bonded in a molecule.
What are the seven diatomic elements ?
Hydrogen (H2) , Nitrogen (N2), Fluorine (F2), Oxygen(O2), Iodine (I2) , Chlorine(Cl2), Bromine(Br2)
What is a lone pair ?
A lone pair is unbonded pair of electrons
Are covalent bonds strong ?
Covalent bonds are strong and require substantial energy to break them .
What is the definition of metallic bonding?
Metallic bonding is the attraction between the positive ions in a regular lattice and the delocalised electrons.
What is a metallic lattice ?
A metallic - lattice is a three-dimensional structure of positive ions and delocalised electrons bonded by metallic bonds.
What are the physical properties of a metallic lattice ?
- good conductors of electricity
- metals usually have a high melting point
- metals are usually malleable and ductile
What does malleable mean ?
malleable means a metal can be hammered into shape without breaking
What does ductile mean ?
Ductile means the metal can be drawn into a wire
Why are metals malleable and ductile ?
Metals are both because the layers of ions can slide over each other, yet the delocalised electrons still attract the ions and hold the structure together.
What is an alloy?
An alloy is a mixture of two elements, at least one of which is a metal, and the resulting mixture has metallic properties.
Why are alloys harder than pure metals?
some of their ions are different size to those of the metal. This distorts the layers of the structure and makes it more difficult for the layers to slide over each other.
What is the equation for finding the % of gold in an alloy?
% of gold in an alloy = number of carats x 100
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What is a giant ionic lattice ?
A Giant ionic lattice is a three-dimensional structure of oppositely charged ions held together by ionic bonds
What are the physical properties of a giant ionic lattice ?
- High melting and boiling point
- soluble in water
- good conductors of electricity when molten/dissolved
What is an aqueous solution ?
An aqueous solution is a solution in which the solvent is water
What are the forces called that hold the separate molecules together in molecular covalent structures ?
Van der Waals’
