Inorganic Chapter 1: Periodicity Flashcards
What is Periodicity?
The idea that trends occur across periods of the periodic table.
What is the periodic table organised by?
Proton number
What happens to atomic radius as you go across the period?
It decreases
What is the trend of ionisation energy across the period?
General increase
Why does melting point increase from sodium to aluminium?
Their metal-metal bonds get stronger
Why does melting point increase sharply from Al to Si?
Silicon has a tetrahedral structure and is macromolecular - strong covalent bonds link it together
Why does melting point decrease from Si to P?
P4 is molecular - only held together by weak VdW forces.
Why does Sulfur have a greater melting point than Phosphorus or Chlorine?
It is larger - stronger VdW forces
P4 vs. S8 vs. Cl2
Why does Argon have such a low melting point?
It exists as single atoms - very weak VdW forces
Why does Ionisation energy generally increase across a period?
There is increasing attraction between the outer shell electrons & the nucleus due to increased number of protons
Why does atomic radius decrease across the period?
Positive charge of the nucleus increases, therefore the electrons are pulled closer and the atomic radius gets smaller.
