Periodicity Flashcards
How and why does sulphur deviate from the trend in first ionisation energy across period 3
It is lower because there’s two electrons in the 3p orbital which repel eachother
State and explain general trend in first ionisation energies across period 3
Increase because larger nuclear charge, but electrons removed from the same energy level
Which element deviates from the general trend in first ionisation energy across period 2
Boron
State and explain trend in atomic radius across period 3
Decreases because there’s the same amount of energy levels in every atom, but more protons so a stronger force of attraction pulling electrons to the nucleus
Where would you find the s, d and p blocks on the periodic table?
S on the far left (group 1 & 2), D in the middle (transition metals), P on the far right
Describe trend in reactivity in group 1 and 2 (s block)
More reactive as you go down a group
Describe the trend in reactivity of the group’s in the D block
More reactive as you go up the group
What structure do sodium, magnesium and aluminium have? (Elements in group 1, 2 & 3 of period 3)
Giant metallic
What is the structure of silicon?
Giant covalent / macro molecular
What is the structure of phosphorus, sulphur and chlorine?
Molecular
State and explain the trend in melting and boiling point across period 3
High in elements in group 1, 2, 3 & 4 but low in groups 5, 6 & 7 due to their structures
Why do the melting and boiling points increase from sodium to aluminium?
Strength of metallic bonding increases because the charge is greater so more delocalised electrons which hold the metallic lattice together
Why does silicon have a higher melting point then phosphorus and chlorine?
It has 8 atoms per molecule and forms a giant structure and has more van der waals
What is the trend in atomic radii down a group?
Increases
Define first ionisation energy
Energy needed to remove one mole of electrons from one mole of atoms
