Module 3.1 Flashcards
How is the periodic table arranged
In groups and periods
In order of increasing atomic number
Metals are on the left and non -metals are on the right
What is a group (periodic table)
A vertical column in the periodic table
Each element in the same group has the same number of electrons in their outer shell
Elements in the same group have similar properties
What are periods (periodic tables)
A horizontal row in the periodic table
There are general trends in the periods
What is periodicity
The trend in properties that is repeated across each period
It can be used to predict the properties of elements
What do all elements in a group have
The same type of orbitals
The same number of electrons in the outer shell
How do you use the periodic table to tell the final subshell of an element
Depending on the ‘block’ of the periodic table
S block = s orbital
D block = d orbital
P block = p orbital
F block = f orbittal
How does atomic radius affect nuclear attraction
The larger the atomic radius, the weaker the nuclear attraction
How does nuclear charge effect nuclear attraction
The greater the charge, the greater the attraction
What is electron shielding
Electrons in inner shells repel outer shell electrons
The more inner shells the larger the shielding effect
How does electron shielding effect nuclear attraction
The larger the shielding effect, the smaller the nuclear attraction is on the outside ekectrons
How does nuclear attraction affect ionisation energy
(Forming positive ions)
The smaller the nuclear attraction, the smaller ionisation energy required
Electrons in the outer shell are removed first as they experience the lowest nuclear attraction
They require the lowest amount of ionisation energy to remove
What is ionisation energy
The energy needed to form POSITIVE ions
It is a measure of how easy it is to lose electrons
What is ionisation
The process where atoms gain or lose electrons to form an ion
Using ionisation energies how can you tell when there is a new shell
Electrons in the same shell require a similar amount of energy to remove
When the electrons between two shells are removed there is a large spike in ionisation energy
How does ionisation energy generally change across periods
Generally ionisation energy increases moving towards the non metals (as nuclear attraction is greater)
Why is the ionisation energy in group 3 lower than group 2
E.g Boron
Beryllium has a full stable orbital
Boron onky has 1 electron in the p orbital, which is easier to remove
(Easier to remove 1 unstable electron to obtain a stable orbital)
Why is the ionisation energy in group 6 lower than group 5
E.g Oxygen
Nitrogen has 3 electrons in the p orbital, it is half full and therefore stable
Oxygen has 2 electrons in the Px orbital
These electrons repel each other, so it is slightly easier to remove one of the Px electrons
How does atomic radius change across the period
It decreases, as there are more protons in the nucleus, so nuclear attraction is stronger, and the shells are pulled inwards