C2 Periodic table Flashcards
how and what did Newlands discover
building on Dalton’s idea he arranged elements in order of mass and noticed that properties of every 8 elements seemed similar (law of octaves)
what didn’t Newlands consider
unfound elements
how did mendelev arrange the elemets
1869 by atomic weights, left gaps for ellemts that had not been discovered
example of elements that did,’t fit in mendelev’s table
argon(greater relative mass) and potassium
this was later solved when noble gases where discovered
what does gropu number tell you
number of electrons in the outmost shell, so every group has similar properties
characterestics of metals
metallic bonding
conduct electricity, higher boiling and melting points, ductile and malleable
characteristics of non metals
electronic insulators, if solids are brittle
where can you found non-metals
top right hand corner
what groups do atoms of elements gain electrons to form negative ions
5,6,7
where can you found metals
left hand side and centre
which groups lose electrons to form positive ions
metals of group 1,2,3
n. of electrons in outmost shell of noble gases
8 so very stable
why are noble gases very unreactive
very stable electon arrangement
when can large noble gases make compounds
with the mosr reactive non metals
what’s the first group name
alkali metals
examples of alkali metals
lithium, sodium potassium
properties of alkali metals
- very reactive, must be stored in oil so don’t react with O
- reactivity increases as you go down the group
- very low densities, FLOAT ON WATER
- very soft
- silvery shiny surface when you cut them until don’t react with O
electronic structure of alkali metals
1 electron in outmost shell
with who and how do alkali metals react
with non metals losing the single electron in the outer shell, so form positive ion with +1 charge(always form ionic compounds)
how do melt and boil points get lower for alkali metals
as you go down the group
how do alkali metals react with
- water
- oxygen
metal flouts moving around and fizzing-caused by reaction with water to form hydrogen gas
2. also produces metal hydroxides which are soluble , solution colorless with high pH
colour of reaction between alkali metals and non-metals
solutions formed colourless, dossolve in water
what are halogens + examples
gropu of toxic non metals that have coloured vapours fluorine chlorine nromine iodine
what are the melting points and boiling for halogens
low, increase going down