Atomic Structure - Types Of Bonding Flashcards
Atomic number
No. of protons
Atomic mass number
No. Of protons + neutrons
Relative mass of protons neutrons and electrons
1 1 and 1/1840
Relative charge protons neutrons and electrons
+1 0 -1
Position of protons neutrons and electrons
Nucleus , nucleus, shell
Who discovered the plum pudding model
JJ Thompson - 1897
Who did the gold foil experiment? When?
Rutherford - 1911
Who discovered the neutron? When?
Chadwick- 1932
Ions are?
Charged particles
Positive ions formed when atoms lose electrons
Negative ions formed when atoms gain electrons
Size of the atom
Atoms have a radius of 0.1 nanometres (nm) or 1 x 10 to the power of -10m
What are isotopes
Atoms of the same element which have the same number of protons but different numbers of neutrons
How to find relative atomic mass - R.A.M
R.A.M = (Mass Number 1 x abundance) + ( Mass number 2 x abundance) / total abundance
What is ionic bonding and what is it called?
Giant ionic lattice
Occurs in metal ions when reacting with non-metal ions.
The positive metal ion transfers one or more electrons to the negative non-metal ion that both end up with full outer shells.
They are attracted by electrostatic attractions.
Properties of Ionic bonds
Strong and lots of heat energy needed to break
Cations and anions
Lose electrons- cations
Gains electrons- anions
What is covalent bonding and what is it called with atoms and then with molecules?
A shared pair of electrons. A molecule is 2 or more atoms covalently bonded together.
Two non metals
Molecular covalent bonding is 2 molecules sharing electrons
Giant covalent lattice bonding is 2 atoms sharing electrons
Properties of ionic bonding/ Giant ionic lattice
High melting and boiling point as strong ionic bonds requires a lot of heat energy to break
Conducts electricity when molten as free electrons to move and carry a charge
Soluble in water
Brittle
Diatomic molecules are?
When 2 of the same atom are covalently bonded together e.g chlorine
Properties of covalent molecules
There are weak forces of attraction - van der waals
Do not conduct electricity as they have no free electrons
Have low solubility in water
Have low melting and boiling points
Allotropes are
Different forms of the same element in the same physical state e.g diamond, graphite and graphene
Metallic bonding and what is it called
Metallic Lattice
The electrostatic attraction between the positive metal ions and delocalised electrons
Only between metals
Diagrams for bonding
Look in book
Properties of metallic bonding
High melting and boiling points- strong attraction
Conducts heat and electricity- delocalised electrons
Strong malleable and ductile - layers of metal ions can Slide Over each other
Flame test colour for -
lithium
sodium
potassium
calcium
copper
Crimson red
orange
lilac
brick red
green-blue
An alloy is?
A mixture of a least two elements one of which is metal
To find percentage of gold -
No. Of carats/ 24 x 100
Why is an alloy a better material than the metal element in terms of structure?
As an alloy has different sizes of atoms . This makes it difficult for the layers to slide and the alloy to break.
What is meant by the term relative atomic mass?
The average atomic mass of an isotope compared to the C-12 isotope
What elements have a double covalent bond and which one has a triple covalent bond
Double - Oxygen, Carbon dioxide
Triple - Nitrogen
What are the allotropes of Carbon?
Diamond, Graphite and Graphene
What is the structure of diamond?
Each carbon atom is covalently bonded to four others in a tetrahedral three-dimensional structure
What are the properties of diamond?
High melting and boiling points
Does not conduct heat or electricity as it has no free ions
Hard due to tetrahedral structure
What are the uses of diamond?
As a cutting tool for hard rock, metals and glass
What is the structure of Graphite
Layer of carbon atoms are arranged in hexagons with weak covalent bonds and forces. Each atoms is bonded to 3 others so one electron is free and it is 3-dimensional
What are the properties of graphite
High melting and boiling points
Good conducteur of heat and electricity as it has a free atom
Soft due to the weak forces between layers
What are the uses for graphite
Lubricants for machinery and pencil leads
What is the structure of Graphene
A single-atom thick layer of graphite with strong covalent bonds between each carbon atom.
The atoms are arranged in hexagons
2-dimensional
What are Properties of Graphene
High melting and boiling points
Good conductor as one electron is unbonded
Very strong as it has strong covalent bonds - 100 times stronger than steel
Light
What are Uses of Graphene
As a strong light and relatively cheap conductor in solar cells and batteries
