Period Ⅲ Elements and Oxides Flashcards
As you move across the period what happens to the atomic radius?
It would decrease as the number of shells stays the same but the number of protons increases and there is similar shielding.
As you move across the period what happens to the 1st ionisation energy?
It would increase across the period generally, however at Al and S there are dips for the reasons mentioned in Atomic structure
As you move across the period what happens to the types of elements?
The first 2 are metals and the rest are non metals
As you move across the period what happens to the melting and boiling points?
The metals contain metallic bonds and so require lots of energy to break and the higher the charge the more delocalised electrons so the more energy is required.
Silicon is macromolecular and contains many strong covalent bonds and so requires more energy than metallic bonds
Cl and P and S are all simple molecular and have weak van der waals forces and require little energy
Although SiO₂ is macromolecular what can it react with?
A strong concentrated alkali as it is still an acidic oxide, such as NaOH
In terms of atomic structure, explain why the van der Waals’ forces in liquid argon are very weak
Argon atoms are single atoms with electrons closer to the nucleus which cannot easily be polarised
Why does the ionic character of the period Ⅲ oxides decrease across the period?
As you progress through the series the electronegativity difference decreases, this means the electrons are less transferred and are increasingly shared.
Why is NaOH more alkali than Mg(OH)₂?
It is more soluble in water
Why is NaOH more alkali than Mg(OH)₂?
It is more soluble in water
What is an oxoacid?
An acid which contains oxygen
Why do the oxide ions in aluminium oxide not react with water?
The high charges of Al and O means that the lattice enthalpy is very high. This would require a lot of energy to break and so is insoluble.
Why does the solution of sulfur trioxide have a lower ph than the solution of sulfur dioxide?
When fully disassociated there are more hydrogen atoms in sulfur trioxide and so a lower Ph
Why does the solution of sulfur trioxide have a lower Ph than the solution of sulfur dioxide?
When fully disassociated there are more hydrogen atoms in sulfur trioxide and so a lower Ph
How can you show that a compound contains ions experimentally?
melt the solids and show how they conduct electricity
Are ionic metal oxides basic or acidic?
They are basic
