2.5 ELECTRONS AND BONDING Flashcards
How many electrons occupy each shell?
1- 2 electrons
2- 8 electrons
3- 18 electrons
4- 32 electrons
What is an orbital?
An orbital can be occupied by two electrons only
Why is the 4S subshell filled first?
The 4S subshell is filled up first as it is slightly lower than the 3D subshell, however electrons are removed from the 4S subshell first.
What are the group blocks?
Group blocks:
group 1 & 2 & helium= s-block
group 3-8 = p-block
transition metals = d-block
lanthanides & actinides = f-block
What are the anomalies?
The anomalies are chromium and copper. One electron in the 4S subshell repels into an empty orbital in the 3D subshell as the 3D subshell is bigger and therefore gives the element more stability
What is ionic bonding?
Ionic bonding is the electrostatic attraction between positive and negative (oppositely charged) ions
What is a lattice?
A lattice is an arrangement of oppositely charged ions
What are the properties of giant lattices?
Properties:
-high melting and boiling points = lots of energy required to overcome strong electrostatic forces of attraction
-dissolve in polar solvents = polar water molecules break down the lattice and surround the ions
-electrical conductivity = non-conductive in solid, conductor as liquid or aqueous
What is a covalent bond?
A covalent bond is the electrostatic attraction between atoms that share a pair of electrons
What is a dative covalent bond?
A dative covalent bond is a covalent bond in which atoms share the same pair of electrons
What is a lone pair?
A lone pair is a pair of electrons not taking part in bonding
What are properties of covalently bonded molecules?
Properties:
-high melting and boiling points = strong electrostatic attraction
-malleable = layers slide over each other
-conductor of electricity = contains delocalised/free electrons
