Atomic structure and bonds Flashcards
The further the shell is from the nucleus, the energy of the electrons is higher or lower?
Higher
Shorthand notation for sodium (NA^11)
a) 1s^2 2s^2 2p^6 3s^1
b) 1s^2 2s^5 2p^6 3s^1
c) 1s^5 2s^2 2p^7 3s^5
d) 1s^2 2s^3 2p^6 3s^7
1s^2 2s^2 2p^6 3s^1
Definition of Valency
Ability of an atom to enter into chemical combination with other elements
What are the 3 types of primary bonding?
Ionic, Covalent and metallic
What are the 2 types of secondary bonding
van der waals forces and hydrogen bonding
During ionic bonding Na -> Na^+ does the electron count go up or down?
Down
During ionic bonding Cl -> Cl^- does the electron count go up or down?
Up
What are the material properties of an ionically bonded material?
High melting and boiling points, high hardness, high youngs modulus
Low ductility/ brittle
Describe ionic bonding
transfer of electrons from one atom to another creating ions.
Describe covalent bonding
Atoms sharing electrons. Electron rings interlinked.
Describe properties of material with only covalent bonds.
High young’s modulus but brittle.
high melting and boiling point.
Describe metallic bonding.
Sharing of the valence electrons between all the atoms present. electrostatic interaction between electron cloud and metal ions -> binds metal together.
Describe properties of material with metallic bonds.
High electrical conductivity.
Good tensile and compressive strength.
High ductility
Are secondary bonds weaker or stronger than primary bonds?
Weaker, but have significant affect on material properties.
What is the main difference between primary and secondary bonding?
No sharing or transfer of electrons.
