First 20 Elements Flashcards
What is metallic bonding and the elements that are bonded with it?
Metallic bonding is when positive metal ions are surrounded by a pool of delocalised electrons.
These electrons are free to move, hence the word delocalised, so that means the can conduct electricity.
Elements are Li, Be, Mg, Al, Na, K, Ca
What is covalent molecular bonding and the elements that are bonded with it?
Covalent molecular bonding is when molecules of two of the same atoms (diatomic) are bonded with covalent bonding.
Elements are HON7 and P4, S8 and C60 (Fullerenes)
What is covalent network bonding and the elements that are bonded with it?
Covalent network bonding is when thousands of atoms are joined together by covalent bonds.
Elements are B, C (diamond and graphite) and Si
Explain the differences between Carbon in the form and diamond and Carbon in the form of graphite.
Carbon in the form of diamond:
Tetrahedral structure
All 4 outer electrons are bonded and held together by covalent bonds
No conduction of electricity
Carbon in the form of graphite:
Hexagonal ring structure
Held together by LDF’s
4th electron is delocalised outer electron, hence conduction of electricity is allowed.
What is monatomic bonding and the elements that are bonded with it?
Monatomic bonding is when single atoms are held together by LDF’s.
Mono = One.
Elements are all of the Noble Gases e.g Group 8
What is electronegativity and its trends in the PT?
Electronegativity is a measure of the attraction an atom has for the electrons in the bond.
It decreases going down a group
It increases across a period
Explain why electronegativity increases across a period.
Electronegativity is a measure of the attraction an atom involved in a bond has for the electrons of the bond.
As you go along a period, a proton is gained each time.
This increase in nuclear charge means that the nucleus is more attracted to the outer electrons of that atom.
This attraction gets stronger as you go across, hence why electronegativity increases as you go across a group.
What is ionisation energy and its trends in the PT?
Ionisation energy is the energy required to remove one mole of electrons from one mole of atoms in the gaseous state.
It decreases as you go down a group.
It increases as you go across a period
Explain why ionisation energy decreases down a group.
Ionisation is the energy required to remove one mole of electrons from one mole of atoms in the gaseous state.
As you go down a group, an extra electron shell is gained each time.
This extra electron shell provides shielding for the outer electrons of the atom, weakening the attraction between the nucleus and outer electrons.
This weak attraction decreases the energy needed to remove one mole of electrons from the gaseous atom, hence why ionisation energy decreases as you go down a group.
What is covalent radius and its trends in the PT?
Covalent radius is the measure of half the distance between the nuclei of two of its bonded atoms
It decreases as you go across a period.
It increases as you go down a group.
