alakline Flashcards
give two observations when lithium reacts with water
bubbles
get smaller and dissappear
floats
give two observations when pottasium reacts with water
catches fire
floats on water
bubbles
explain why lithium is less reactive than pottasium
refer to atomic structure
li has a smaller atomic radium
so valence electron is attracted strongly to nucleus
cant be easily lost as k
give observatio would be different if k used instead of li
burn with a flame
reacts more vigrous
form a ball
identify the most reactive metallic element in the periodic table
francium
the elements in group 1 show a clear trend in some of the phisical proprities
identify the phisical property that shows a clear trend
melting point
when a peice of lithium is removed from the oil dried and cut the exposed surface
changes from shiny to dull
why lithium and sodium have simillar reactions with water
they have one electron in their valence shell
is melting point decrease or increase down group of alkaline metal
decrease
is denisty increase and decrease down group
increase
phisical properties of alkali metals
they have shiny silvery surface when freshely cut with a knife
they are soft metals
have low densties
they are good conductor of electricity and heat
they have low melting point
give me melting point of lithium
180
give me melting point of pottasium
64
why pottasium floats on water
as its less dense than waTER
WHAT IS THE lightest alkali metal
lithium
why they are called alkali metals
as they react with water forming alkaline solution
why reactivity of alkali metal increase on descending group
as number of shells increase so distance between the valence electron and nucleus increases thus the valence electron is less firmly held to the nucleus and cant be lost easily
sources of sodium chloride
sea water,ground rock salt deposits
where metals are stored
store under oil /keresone
why metals are store under keresoine
to isolate them from air and water
observation when alkali react with oxygen
give a white oxide layer
difference of li and k and na
lithium doesnt give a flame
na gives yellow flame
k gives a lilac flame
why reaction is more violent in case of patossium than in case of sodium
pottasium is more active than sodium
example of chemical equation alkali metal reacts with water
2li+2h2o=2lioh
+h2
reaction alkalis with air
4na+o2=2na2o
reaction alkali with halogen
2na+cl2=2nacl
uses of sodium
used in extraction of titanium
Uses of tatinum
Make body of rockets
Chemical equation of extraction of titanium
Ticl3+3Na=>Ti +3Nacl
What is meant by reactivity of metals
Tendency to lose it’s valence electron
Observe li when put in cold water
Gas fizzes around it,float,metal chamge into ball and get smaller and disappear
Observation when k put in cold wayer
React violently,melt immediately, catch fire with lilac flame,floats,change into ball and get smaller and disappear in water
