Exam Cards - Unit 1: Electrons, Bonding & Structure Flashcards
(21 cards)
Define atomic orbital.
A space in which two electrons with opposite spins can inhabit.
Within a shell, state the number of s-, p-, d-, and f-orbitals.
s = 1
p = 3
d = 5
f = 7
How many electrons can an orbital hold?
2
Define sub-shell.
A group of the same type of atomic orbitals within a shell.
Define principle quantum number.
A number representing the relative overall energy of each orbital, which increases with distance from the nucleus.
What is the first ionisation energy of an element?
The energy needed to remove one electron from each atom in one mole of gaseous atoms to form one mole of gaseous 1+ ions.
Which three factors affect the nuclear attraction experienced by an electron?
Atomic radius, nuclear charge, and electron shielding/screening (inner shells of electrons repel outer-shell electrons).
What is the second ionisation energy of an element?
The energy needed to remove one electron from each ion in one mole of gaseous 1+ ions to form one mole of gaseous 2+ ions.
Define ionic bond.
An electrostatic attraction between two oppositely charged ions.
Why are ionic compounds able to conduct electricity when molten or dissolved?
The ions in a liquid are free to move and they carry a charge.
Why do ionic compunds have high melting points?
They are held together by strong electrostatic forces, so it takes high amounts of energy to overcome these forces.
Why do ionic compounds tend to dissolve in water?
Water molecules are polar so they pull ions away from the lattice, causing it to dissolve.
Define covalent bond.
The sharing of electrons between atoms.
Define a dative covalent bond.
A shared pair of electrons which has been provided by one of the bonding atoms only.
Define allotrope.
Different forms of the same element in the same state (e.g. diamond and graphite)
What structure do metal elements have?
Giant metallic lattice structures.
Define metallic bonding.
When positive metal ions are attracted to the delocalised negative electrons, forming a lattice of metal ions and a ‘sea’ of delocalised electrons.
How does the number of delocalised electrons affect the melting point of a metal?
More delocalised electrons per metal ion cause the metallic bonding to be stronger.
Why are metals good electrical conductors?
The delocalised electrons can carry a current.
Which is the strongest intermolecular force?
Hydrogen bond.
Define Van der Waals forces.
Attraction between induced dipoles of neighbouring molecules.
