Periodic table Flashcards
ELements in same group tend to have _________________
similar chemical properties
Size of atom becomes _____ across a period, from left to right
smaller
Why does reactivity increase down Group 1 metals (can compare sodium and caesium)
The caesium atom has a larger atomic radius than sodium atom, thus its delocalised valence electron is held further from the nucleus. This mean its valence electron is less strongly held and more easily lost, making caesium more reactive than sodium
Properties of transition metal (5)
1) High mp and bp
2) High densities
3) show variable oxidation states in their cmpds
4) form coloured compds
5) Are used as catalysts
Properties of alkali metals (4)
1 low mp bp
2) low density
3) colourless
4) one oxidation state when forming cmpds
Going down the Alkali metals group, melting point _________ density ____________, reactivity ____________, state changes from _____, to ____, to ___
Density increase
MP decrease
reactivity increase
state change from solid, to liquid to gas
Going down halogen group colour becomes _____, reactivity ____, mp _____
colour darker
reactivity decreases
mp increases
When a more reactive halogen react with less reactive halide cmpd, what happens
Less reactive halide ion lost an electron to mroe reactive halogen. less reactive halide ion oxidised by more reactive halogen
Why mp increase down halogen group
Molecular size increase meaning a larger surface of interaction between molecules so Larger molecules down the group have stronger intermolecular force of attraction. More energy is required to break these stronger forces thus melting point is higher
Special characteristic of noble gases
generally unreactive and inert
why reactivity of halogens decrease down te group
Down the group, atomic radius increase. This decrease the tendency of the halogens to gain electrons
Why atomic radius decrease across a period
nuclear charge increase
number of shielding electrons is constant
Hence valence electrons are increasing closer to nucleus, atomic radius decrease
Why atomic radius down the group increase
nuclear charge increase
no of shielding electrons increase
But each element has one more shell of electrons so valence electrons are increasingly further from nucleus and atomic radius increase
