The periodic table Flashcards
ionisation
when an atom loses or gains an electron.
first ionisation energy
The first ionisation energy is the energy required to remove one mole of the most loosely held electrons from one mole of gaseous atoms to produce 1 mole of gaseous ions each with a charge of 1+.
how does atomic radius affect ionisation energy?
larger the radius, smaller the nuclear attraction experienced, so the ionisation energy is less.
how does nuclear charge affect ionisation energy?
higher the nuclear charge the larger the attractive force, so ionisation energy is more.
how does electron sheilding affect ionisation energy?
inner shells repel the outer shell electrons because the are all negative. this repulsive force is called shielding.
the more inner shells, the larger the effect of shielding, and the smaller the nuclear attration experienced by the outer electrons, so ionisation energy decreases.
trends across a period
- General increase in ionisation energy
- No. protons in nucleus increase, so there is a higher attraction on the electrons
- electrons added to same shell, so outer shell is drawn in closer.
- same No. inner shells, so shielding will hardly change
trends down a group
- General decrease in ionisation energy
- No. shells increase, so distance between nucleus and outer electrons increase, so weaker force of attraction
- More inner shells, so shielding effect increases, so weaker attraction.
metallic bonding
positive ions occupy fixed positions and eletrons are delocalised.
giant metallic lattice
- electrons can move
- have high melting/boiling points
- good conductor of electricity
solubility of group 2 metal hydroxides
solubility in water decreases down the group, and so does the alkalinity.
how do the halogens boiling points change down the group
it increases
reactivity of halogens
- very reactive and electronegative
- reactivity decreases down the group
