Periodicity Flashcards
1st Ionisation energy
the energy required to remove an electron from a gaseous atom
1st Electron affinity
energy change when an electron is added to a gaseous atom
Electronegativity
the measure of the ability of an atom to attract a pair of bonded electrons
Across a period, the atomic radius _______ because (2 parts)
- electrostatic attraction between protons and electrons increases as the atomic number increases
- electrons are added to the same shell
down a group, atomic radii _____ because
increase, extra energy levels are added
Electronegativity
______ across a period
_______ down a group
increases, decreases
First ionisation energy _____ down a group because
decreases, there is more shielding, the valence electrons are further from the nucleus
first ionisation energy _____ across a period because
Increases, protons are added that attract the electrons
Na2O reaction with water
Na2O + H2O → 2NaOH (strong base)
MgO reaction with water
MgO + H2O → Mg(OH)2 (weak base)
P4O10 reaction with water
6H2O + P4O10 → 4H3PO4
SO3 reaction with water
SO3 +H2O → H2SO4 (strong acid)
Ionic oxides are (basic/acidic)
basic
covalent oxides are (basic/acidic)
acidic
which group 3 element is amphoteric?
Aluminium
Why does the melting point increase down group seven
group seven has van der Waals intermolecular forces, and as you go down the group, there are more electrons, which means more V.d.W forces
Why does the melting point decrease down group one?
because the ions are bigger, so the charge is more spread out and the metallic bonds are weaker
Down group 1, reactivity _____
increases
down group 7, reactivity ____
decreases
reaction of Li with water
2Li(s) + 2H2O(l) → 2LiOH(aq) + H2(g)
reaction of Na with water
2Na(s) + 2H2O(l) → 2NaOH(aq) + H2(g)
reaction of K with water
2K(s) + 2H2O(l) → 2KOH(aq) + H2(g)
Which element ends up as an ion in a halide/halogen reaction?
the more reactive element
example of halogen reaction with halide ion
Cl2 + I- → Cl- + I2
Cl2 (chlorine) colour-
green
Br2 (bromine) colour
brownish red
I2 (iodine) colour
purple
