Bonding Flashcards
How is a compound formed
When different elements chemically react and form bonds with each other
How is a molecule formed
Elements are made up of just one type of atom sometimes joined to other atoms of the same element by chemical bonds
When does ionic bonding occur
Between a metal and a non metal
When does covalent bonding occur
Between non metals only
When does metallic bonding occur
With pure metals only
What is a chemical bond
An attraction between two or more atoms
What is an ion
An atom or group of atoms that have an electrical charge either posotive or negative
What is a noble gas
An atom with a full outer shell
How does an atom become an ion
By either gaining or loosing electrons to get an overall charge
What is the definition of ionic bondin
An electrostatic attraction between oppositely charged ions
Where are alkali metals found on periodic table
Group1
Where are halogens found in the periodic table
Group7
How are ionic bonds formed
If you have sodium then it has 1e- in its outer shell by loosing this electron it is now posotive chlorine has seven E- in its outer shell and so gains the electron that sodium has lost making it negative this posotive and negative attracts
What ion does zinc form
Zn+2
What ion does zinc form
Zn2+
What ion does silver form
Ag+
What ion does hydrogen form
H+
What ion does ammonium form
NH4+
What ion does iron form
Fe2+ or Fe3+
What ion does nitrate form
No3-
What ion does hydroxide form
OH-
What ion does hydrogencarbonate form
HCO3-
What ion does carbonate form
CO3-2
What ion does sulphate form
SO4-2
What ion does lead (II) oxide form
Pb+2
What ion does iron (III) oxide form
Fe+3
What ion does copper (II) Sulphate form
Cu+2
What are the properties of ionic compounds
White crystals
Not volatile
Hugh melting points
Insulators
Soluble in water
Conduct electricity
Insoluble in cyclohexane
What are the four different types of compounds
Ionic compounds
Simple molecular covalent compounds
Giant molecular covalent compounds
Metallic compounds
What is an ionic compund
A compound that contains ions
What is an iron lattice
Millions and millions of irons are packed together in a regular lattice arrangement joined by strong ionic bonds between oppositely charged ions
And why do ionic compounds form crystals
Due to the regular structure of the ionic lattice
What are the advantages of representing ionic compounds in circular 2-D format
It shows how each ion is surrounded by oppositely charged ions
It shows the ions closer together and without using stick to connect them
What are the disadvantages of representing ionic compounds in a circular 2-D format
It only shows the ions into dimensions
It doesn’t show the difference in ionic size
What are the advantages of representing ionic compounds in 2-D electronic structure way
Shows the electronic structure of ions
The charges on the ions
The ratio of ions in the formula
What are the disadvantages of representing ionic compounds in 2-D electronic structure way
Doesn’t show how the ions are arranged in the lattice
What are the advantages of representing ionic compounds in a stick diagram
Shows how the ions are organised in the lattice
Arrangement of ions can be seen and the empirical formula determined
Represents the structure in 3-D
What are the disadvantages of representing ionic compounds in a stick diagram
The ions are not so widely spaced and the sticks do not really exist
It doesn’t show the difference in ionic size
What is the advantage of representing ionic compounds in 3-D balls
It shows the structure in 3-D
The ions are close together
No sticks
What are the disadvantages of representing ionic compounds in 3-D balls
Difficult to determine the arrangement of ions
Doesn’t show the difference of the ionic size
Why are ionic compounds solid at room temperature
Ionic bonds are strong and a lot of heat is needed to break them larger ionic charges produce stronger ionic bonds and so much more heat is required to break the ionic bonds
Why can ionic compounds not conduct electricity as a solid
Because that ions are bonded together in the lattice and so ions in solid state cannot move
Why can ionic compounds conduct electricity when liquid
The ions can break free of the lattice and are able to move the ions are charged particles and so can carry an electric current
What is a covalent bond
The shared pair of electrons
How does covalent bonding work
If you have two hydrogen atoms with one electron each they will bond together share the electrons and have two electrons on the outer shells
How do you draw a covalent bond
Like a Venn diagram
What are the properties of simple molecular compounds
They smell easy to change state insulator is generally insoluble very soluble in cyclohexane
Do you simple molecular substances have high or low melting and boiling points
Low
What are intermolecular forces
Weaker forces of attraction between molecules
What breaks when a simple molecular substance melts
Is the intermolecular forces
What is a giant covalent structure
Vast network of atoms E.g diamonds
Do giant covalent structures have a high or low melting point
Hi because of the covalent bonds between the atoms
What are allotropes
Different forms of the same element
What is the property of diamonds
Hard
Very high melting and boiling point
Cannot conduct electricity
What is Graphene
One layer of graphite
Why can graphites layers rub away
Due to the weak intermolecular forces between them and due to it being in layers
Why can graphite conduct electricity
Because it has a delocalised electron which is free to carry electricity
What are fullerenes
A third class of carbon compounds
What are some uses of fullerenes
Nonstick slippery coating for machinery
Cages to hold drug molecules that can be delivered directly into the body
Chemical sponges to soak up toxic substances in the body
Molecular serves which trap large particles like viruses while allowing smaller healthy particles to past three
When was fullerenes discovered
1985
What are metals
Giant structures of positive ions
What is metallic bonding
What is a metal has a delocalised electron and is free to move through the structure of the metal atoms become positively charged ions and are attracted to the Sea of electrons
Why do metals have high melting points
It is due to the strong attraction between the positive charge metal ions and the sea of electrons
Why are metals strong
What are metals hit the layers of metal ions are able to slide over each other answer the structure does not shatter the metallic bonds do not break because the delocalised electrons are free to move throughout the structure
How do metals conduct heat and electricity
Do you localised electrons in metallic bonding allows metals conduct heat and electricity
What is an alloy
A mixture containing one or more metal elements
Why is gold usually an alloy
Because otherwise it’s uses like jewellery unsustainable because the pure gold would be too soft size mixed usually with copper and silver
What is 24 carat gold
99.9% gold
What is 18 carat gold
75% gold and 25% other metals
What is 12 carat gold
50% gold
What is most iron extracted four
To make steel
What is pig Iron
Iron produced by the blast furnace
What is cast-iron
96% iron pig iron which has been re-melted and cold
Impurities make it very brittle
Used for manhole covers and drain pipes
What is root iron (pure iron) used for
Ornamental gates and railings it is very soft
What is the structure in iron
Particles are all the same size
Particles slide past each other
What is the structure in steel
Particles are different sizes this stops the particles sliding past each other
What is shape memory alloy
A type of smart material made from metal is returned to its original shape after being deformed
What is nitinol
A shape memory alloy made from nickel and titanium
