GROUP 2 Flashcards
trends in atomic structure
increase down the group as the atoms has more shells of electrons who make the atoms bigger so there is a decrease in effective nuclear charge with successive elements because of the increased shielding and so the electrons are held more firmly in the nucleus.
trends in ionic radius
decreases because it loses one shell of electrons and the remaining proton hold onto the electrons more strongly and tightly
trends in melting points
decreases down the group, the metallic bond will weaken as the atomic size increases, the distance between positive ions and delocalised electrons will increase therefore the electrostatic attractive forces between positive ions and delocalised electrons will weaken
trends in first ionisation energy
the outermost electrons are held more weakly because they are successively further from the nucleus in the additional shell. the outer shell electrons become more shielded from the attraction of the nucleus by repulsive forces of the inner electrons
how does magnesium react with steam
magnesium reacts with steam to produce magnesium oxide and hydrogen and burns to give a. white flame
magnesium with warm water
magnesium reacts with warm water to give magnesium hydroxide as the product, this produces fizzing and is slower reaction so no flame will be produced
trend in solubility of hydroxides
Mg(OH)2, Ca(OH)2, Sr(OH)2, Ba(OH)2
what is Mg(OH)2 used for
milk of magnesia, neutralise excess hydrochloric acid in the stomach and reduce stomach indigestion
what is titanium oxide used for
reacts with carbon and chlorine to form titanium chloride which is purified by fractional distillation and reduced to titanium using magnesium
what is Ca(OH)2 used for
neutralise acidic soil
what is caO and CaCO3 used for
remove SO3 from flue gases
trends in solubility of sulphates
baSO4, srSSO4, caSO4, mgSO4
what is baSO4 used for
can be ingested to visual soft tissue imaging
what is acidified BaCL2 used to test
presence of sulphate ions as barium sulphate will form a white precipitate, the solution needs to be acidified to remove sulphates which could form a white precipitate
