OZ - Periodicity Flashcards
State which two elements from the first 20 elements of the modern periodic table are not arranged in order of increasing atomic mass
Potassium and argon
Why does they modern periodic table not arrange some elements in order of increasing atomic mass?
They are arranged in increasing atomic number
Explain the difference in melting point between Na and Mg
- Magnesium ions have a greater charge
- As magnesium has more electrons
- So magnesium has stronger metallic bonds
EXplain the difference between the melting points of S8 and Cl2
S8 has intermolecular forces
S8 has stronger intermolecular forces
Explain teh decrease in atomic radii accross the period from Na to Cl
Nuclear charge increases
SHielding remains the same
So greater pull
Explain why the first ionisation energies show a general increase from Li to Ne
Radii decreases
Nuclear charge increases
SHielding stays the same
Which element has the largest atomic radius?
K
Explain why first ionisation energies show a general increase across period three
Increasing number of protons
So increasing nuclear charge
Same shielding
Stronger nuclear attraction
Predict, with reasons, the identity of element X
Large jump between 4th and 5th
So element is in group 4
Si
Predict and explain whether a barium ion is larger, smaller or the same size as a barium atom
Smaller
As there is less electron repulsion
Explain why Li has a high boiling point
Giant metallic structure
How does C conduct?
Delocalised electrons
Explain why carbon has a higher boiling point
Giant covalent structure with layers
Explain why nitrogen is a poor conductor
No electrons to conduct electricity
Explain why nitrogen has a low boiling point
Weak, intermolecular forces
As it is a simple molecular structure
