2.2 Flashcards
(30 cards)
what is an orbital
a region around the nucleus that cab hold up to 2 electrons, each with opposite spin
what are the 4 types of orbitals?
s,p,d,f
shape of s orbital?
spherical
shape of p orbital?
dumbbell
how many orbitals fit into s sub shells
1
how many orbitals fit into p sub shells
3
how many orbitals fir into d sub shells
5
which orbital is filled and empties before 3d
4s
what are the 3 rules for writing out electrical configuration?
- lowest energy orbital is filled first
- for orbitals with the same energy, electrons occupy orbitals singly with the same spin before pairing
- no orbital holds more than 2 electrons
what is ionic bonding?
electrostatic attraction between positive and negative ions. occurs between a metal and non-metal. electrons are transferred from the metal to the non-metal to non -metal so both elements achieve a full outer shell.
how are giant ionic lattices formed?
when the electrons are transferred, it creates charged particles called ions. oppositely charged ions attract each other through electrostatic forces to form giant ionic lattices.
how can the attraction of an ion change?
- ions with a greater charge will have a greater attraction to other ions resulting in stronger forces of attraction therefore stronger ionic bonds
- larger ions that have a greater ionic radius will have a weaker attraction to the oppositely charged ion as the forces will have to act over a greater distance
what are the physical properties of ionic bonding?
- substances with ionic crystal structures have a high melting point and boiling point because the electrostatic forces holding the ionic lattice together are strong - require lots of energy to overcome
- when molten/aqueous, ionic substances can conduct electricity as the ions separate and are no longer held in lattices therefore they are free to move and carry a flow of charge
- in a solid state, ions are in fixed positions with no mobile charge carrier so cannot conduct electricity
- ionic substances are often brittle metals. when the layers of alternating chargers are distorted, like charges repel, breaking there lattice into fragments
what is covalent bonding?
- the strong electrostatic attraction ion between a shared pair of electrons and the nuclei of the bonded atom
- between 2 nonmetals, electrons are shared between two outer shells in order to achieve a full outer shell. multiple electron pairs can be shared to produce multiple covalent bonds
how does the length of a covalent bond relate to its strength?
shorter bonds tent top be stronger (atoms are held closer together so force of attraction are greater, requiring more energy to overcome) double/triple bonds = stronger than single bond
what is used as a measure of covalent bond strength?
average bond enthalpy
dative covalent bonds
form when both of the electrons in the shared pair are supplied by a single atom. indicated using an arrow from the lone electron pair
what is the shape of molecules determined by
the number of electron pairs around the central atom and repulsion between them
- each electron pair naturally repels each other so that the largest possible bond angle exists
VESPR theory
BP-BP<BP-LP<LP-LP
define electronegative
the ability of an atom ton attract the bonding electrons in a covalent bond towards itself
how does electronegativity vary along a period?
increases, atomic radius decreases and charge density increases
how does electronegativity vary down a group?
decreases, shielding increases and atomic radius so charge density decreases
what scale is used to test electronegativity
pauling scale
permanent dipoles
if the 2 two atoms that are bonded have different electronegativities, a polar bond forms. the more electronegative atom draws more of the negative charge towards itself and away from other atom, producing a slightly + and - region
