Chemistry GSCE (AQA) Flashcards
What is Ionic bonding?
Ionic bonding occurs in compounds formed from metals combined with
non-metals.
What are the 3 main types
of bonding?
- Ionic bonding.
(Metal and non-metal) - Covalent bonding.
(Non-metal atoms ONLY) - Metallic bonding.
(Metal atoms ONLY)
What is Covalent bonding?
Covalent bonding occurs in most non-metallic elements and in
compounds of non-metals.
A covalent bond is a chemical bond that involves the sharing of electrons to form electron pairs between atoms.
These bonds between atoms are strong.
Some covalently bonded substances have giant covalent
structures, such as diamond and silicon dioxide. Some covalently bonded substances have very large molecules,
such as polymers. Covalently bonded substances may consist of small molecules.
What is Metallic bonding?
Metallic bonding occurs in metallic elements and alloys. Metallic bonding is found in metals and their alloys. When the atoms give up their valence electrons, they form ions. These ions are held together by the electron cloud surrounding them.
Metals consist of giant structures of atoms arranged in a regular
pattern. The electrons in the outer shell of metal atoms are delocalised and
so are free to move through the whole structure
What is an ionic compound?
An ionic compound is a giant structure of ions. Ionic compounds are
held together by strong electrostatic forces of attraction between
oppositely charged ions. These forces act in all directions in the
lattice.
What are the properties of Ionic compounds?
These compounds have high melting points and high boiling points.
When melted or dissolved in water, ionic compounds conduct
electricity because the ions are free to move and so charge can flow.
What are polymers?
They’re long chains of molecules made up from many repeating small molecules called monomers.
What are giant covalent structures?
Substances that consist of giant covalent structures are solids with
very high melting points. All of the atoms in these structures are
linked to other atoms by strong covalent bonds. These bonds must
be overcome to melt or boil these substances. Diamond and
graphite (forms of carbon) and silicon dioxide (silica) are examples
of giant covalent structures.
Students should be able to recognise giant covalent structures from
diagrams showing their bonding and structure.
What are the properties of metals and alloys?
Metals have high melting and boiling points.
In pure metals, atoms are arranged in layers, which allows metals to be bent and shaped. Pure metals are too soft for many uses and so are mixed with other metals to make alloys which are harder.
Structure and bonding of carbon. /Covalent
structures.
Diamond:
In diamond, each carbon atom forms four covalent bonds with other
carbon atoms in a giant covalent structure, so diamond is very hard,
has a very high melting point and does not conduct electricity.
Graphite:
In graphite, each carbon atom forms three covalent bonds with
three other carbon atoms, forming layers of hexagonal rings which
have no covalent bonds between the layers.
In graphite, one electron from each carbon atom is delocalised.
How do you name an ionic compound?
- First part of the name is
a metal. (this doesn’t
change). - Second part is a non-
metal. (this changes).
What is a Giant ionic lattice?
A giant ionic lattice is a giant structure of ions with a regular repeating arrangement.
How are covalent compounds formed?
They’re formed from 2 non-metal atoms that share electrons and form simple molecules.
Give 2 examples of an ;
1. Ionic compound
(Metal and non-metal)
2. Covalent compound
(Non-metal)
- CuO , NaCl2 , FeSO4 ,
K2O , MgCl2. - CO2 , O3 , Cl2 , NH3 ,
H2O.
What is the bonding structure for metallic bonding?
Metal ions in a sea of delocalised,free electrons.
