7. Periodicity Flashcards
What is the first ionisation energy
The energy required to remove one electron from each atom
In one mole of gaseous atoms of an element to form one mole of 1+ ions
Successive ionisation energies from an element in period 3- name the element
1-578 2-1817 3-2745 4-11577 5-14842
There is a large increase from 3rd to fourth ionisation energies
The fourth electron must be removed from an inner shell
Element must be aluminium
Explain structure of metals
Electrostatic forces of attraction between positive metal ions
In a sea of delocalised electrons
How does nuclear charge affect ionisation energy
More proteins in nucleus, the more positively charged the nucleus
the stronger the attraction of electrons
How does atomic radius affect ionisation energies
Attraction falls with distance from nucleus.
Electron close to nucleus will be more attracted than one forget away
Periodic table is arranged
In elements of increasing atomic number
Elements in same group show trends in
Chemical properties
Why id there a decrease in ionisation energy from group 2 to 3
Group 2 electrons remove electrons from s orbital while group 3 elements remove electrons from p-orbital
P-orbitals have higher energy levels
Therefore further from nucleus so lower ionisation energy
Why do Ionisation energies decrease down groups
Although more nuclear charge this is outweighed by
More shells so more atomic radius and more electron shielding from electrons inner shells
What are allatropes
Different forms of same element in same state
Explain structure of diamond
Each carbon atom is bonded to four other carbon atoms in a tetrahedral shape in a lattice structure
Explain structure of graphene
Single sheet of carbon atoms joined together in hexagons
Single layer of atoms so two dimensional compound
Graphite is made up of multiple layers of graphene
Multiple layers of carbons in hecagons
Layers are held by weak induced dipole-dipole interactions
Every carbon is bonded to three others with 1 delicalised electrons
