Periodicity Flashcards
Groups on periodic table
Vertical columns of elements with the same chemical properties and outer electron arrangement.
Periods on the periodic table
Horizontal rows of elements increasing in atomic number and outer electron arrangement as you go along from left to right.
Metallic lattices examples
Lithium, Beryllium, sodium, calcium, aluminium magnesium, potassium.
Covalent network examples
Boron carbon and silicon
Covalent molecules example
Nitrogen, phosphorous, oxygen, sulphur, fluorine and chlorine and hydrogen
Monatomic elements examples
helium, Neon and argon
Metallic lattice properties
Metallic bonding
Lattice structure
High melting and boiling point
Conducts electricity
Covalent molecular properties
Covalent bonding
Molecule structure
Low melting and boiling point due to weak intermolecular forces.
Doesn’t conduct electricity
Covalent networks properties
Covalent bonding
Network structure
High melting and boiling points.
Diatomic elements
hydrogen, nitrogen, fluorine, oxygen, iodine, chlorine, bromine.
Forms of the element carbon
Diamond, graphite and buckyball (molecular)
Fullerenes definition
Large carbon molecules which have covalent bonding and molecular structure.
Phosphorous
P4
Sulphur
S8
Covalent radius definition
Half of the distance between the nuclei of two atoms that are covalently bonded together.
Covalent radius rule down a group
As you go down a group the covalent radius increases because an extra outer electron shell is present, increasing the distance from the nucleus to the outer electron shell and also causing more electron shielding,
Covalent radius rule along a period
As you go along a period the covalent radius decreases because a proton is added to the nucleus, giving it an extra positive charge, which pulls the electron shell closer to the nucleus (no extra electron shells are added).
Covalent radius rule along a period
As you go along a period the covalent radius decreases because a proton is added to the nucleus, giving it an extra positive charge, which pulls the electron shell closer to the nucleus (no extra electron shells are added).
Covalent radius rule for metal atoms turning into ions
Atoms lose their a outer electron shell when turning into ions, this decreases the covalent radius since the distance between the outer electron shell and the nucleus has decreased.
Covalent radius metal atoms to ions
Atoms lose their a outer electron shell when turning into ions, this decreases the covalent radius since the distance between the outer electron shell and the nucleus has decreased.
Covalent radius rule for non metal atoms to ions
When a non metal atom is turned into a non metal ion the ions covalent radius increases because electrons are received to fill the outer electron shell, this increases the outer electron shielding and no protons are added to the nucleus so the radius increases.
First ionisation energy definition
The energy required for the first electron to be lost from all the atoms in one mole of free atoms.
Things to remember about ionisation energies
They always form positive ions
They are always gas
Ionisation equations
First A(g) —> A+(g) + e-
Second A+(g) —> A2+(g) + e-
Third A2+(g) —> A3+(g) + e-
Going along a period ionisation energy rule
As you go along a period from left to right the ionisation energy increases because the positive charge in the nucleus increases due to additional numbers of protons, this causes the outer electrons to be held tighter and closer to the nucleus, and no extra electron shells are added.
Going down a group ionisation energy rule
As you go down a group the ionisation energy decreases since their is more electron shells, this means that the outer electrons have more shielding and are further away from the nucleus, meaning they are less tightly held and so less energy is required for them to be lost.
Electronegativity definition
The measure of the force of attraction an atom involved in a bond has for the shared electrons of the bond.
Electronegativity along a period
As you go along a group the number of protons increases, this increases the strength of the positive charge of the nucleus, meaning the shared outer electrons are more tightly held, therefore meaning that as you go along the group the Electronegativity increases.
Electronegativity down a group
As you go down a group the number of outer electron shell increases, this increases the electron shielding of the shared electron and the distance of the nucleus, therefore this means that as you go down a group the Electronegativity decreases.
