Periodic Table Flashcards
How many elements are there
How many occur naturally
118
94
What is the trend of G1
Reactiviy
Softness
Density
Melting+boiling
Increases down the group
Increases
Increases
Decreases
Why are they called alkali metals
When reacted with water they form an alkaline solution
Physical properties of alkali metals(2)
Relatively soft
Relatively low density and melting points
Tarnish?
What is the general formula for G1+water
Metal+water=metal hydroxide+hydrogen gas
What is lithiums reaction with water
It floats as it is less dense, there is effervescence and it moves around due to the hydrogen gas being given off
Dissolves to form aqueous solution of LiOH
How does sodium react with water
Melts, floats, moves around on surface vigorously, effervescence and hydrogen gas
Dissolves to form NaOH
How does potassium react with water
Enough heat is produced to light the hydrogen gas and a lilac flame is produced, hops around
Explain the trend in reactivity of G1
The more easily the valence electron is lost the more reactive it is, the further down the group, the bigger the atom, the further away the electron is to the nucleus, the smaller the electrostatic attraction
What was the first halogen to be discovered and where was it used
Flourine, in mineral fluorospar in ceramics
How was chlorine extracted/discovered
From hcl
How was bromine extracted/discovered
Bubbling chlorine gas through water sample
How was iodine extracted/discovered
Burning seaweed and treating the ashes with sulfuric acid to produce a purple vapour
How was astatine extracted/discovered
Bombarded bismuth with radiation
Use of chlorine
To disinfect
Use of bromine
To disinfect
Use of Florine
To help medical drug enter cells
Use of iodine
Prevent infection
Use of satiating+all halogens
Energy efficient lamps
Why is GVII called halogens
It means salt producing, when reacted with metals salts are produced
What is the trend for colour in GVII + state fl,cl,br,I
Darkness decreases down
Yellow-green gas
Green gas
Red liquid
Dark purple solid
Trend of GVII
Density
Melting points
Reactivity
Increase
Increase
Decrease
Explain the reason for the trend in reactivity in GVII
Hal go gens have 7 valence electrons and react by attracting other electrons to fill their outer shell. As you descend down the group, the number of shells increase and the ability to attract the electrons decreases
What happens When a more reactive element comes into contact with a less reactive element in a compound
A displacement reaction
What is the trend of metallic characteristics across and down the periodic table
Explain why these characteristics occur
The metallic characteristics decrease as you move right across a period, and increase as you move down a group.
This is because non-metal atoms are more readily accepting to electroms to fill their valence shells.
What are the physical properties of alkali metals
Soft and can be cut with a knife
What happens when alkali metals react with air
Metal oxides form
What does it mean if an element is diatomic
It forms molecules consisting of 2 atoms
What are the trends of the alkali metals
As you move down the group:
The melting and boiling points decrease and the metals become more reactive
What are the chemical properties of alkali metals
They all easily lose their one valence electron so they have similar chemical properties
They react with oxygen to form metal oxides
They react with water to form metal hydroxides
What is the state of fluorine (and colour) at room temperature, then the colour in a solution
Yellow gas, pale yellow in solution
What is the state of chlorine (and colour) at room temperature, then the colour in a solution
Pale yellow-green gas
Green-blue in solution
What is the state of bromine (and colour) at room temperature, then the colour in a solution
Red-brown liquid that readily evaporates to form a brown gas
Orange in a solution
What is the state of iodine (and colour) at room temperature, then the colour in a solution
Grey-black solid that readily sublimes to a purple gas
Dark brown solution
How do halogen replacement reactions work
When a more reactive halogen replaces a less reactive halogen, reactivity decreases down the group
How do we test for halides
We take an unknown halide solution dissolved in nitric acid and then we add silver nitrate or Pb(NO3)2 and check the colour of the precipitate formed
What color precipitate is AgCl
White
What color precipitate is AgBr
Cream
What color precipitate is AgI
Yellow
What are the general properties and uses of transition metals
Hard,strong with high MP and density.
Form coloured compounds as elements and in compounds
Have ions with variable oxidation numbers (iron (II) and iron (III))
Titanium=limb replacement
Dyes, stained glass jewelry
Why are transition elements often used as catalysts
Because of their ability to easily interchange between oxidation states
What are the general properties of noble gases (4)
Very low MP+BP
Full outer shells
Chemically inactive, inert and unreactive due to their stable electronic configuration
Monatomic colour less gases
What are the uses of noble gases
Helium->balloons, less dense than air and doesn’t burn
Neon,argon and xenon->advert signs
Argon->inert atmosphere for welding
Argon->fill electrical bulbs
What is group 6 of the periodic table called
The chalcogens
How do we test the reactivity of alkali metals
By reacting them with water
How do we further confirm the presence of halide ions
Cl
Br
I
We add aqueous ammonia
Soluble(clear)
Partially soluble
Insoluble(visible precipitate)
Periodic table
Arrangement of elements in periods and groups and in order of increasing proton number
Reactions of halogens
Displacement reactions with halides, the more reactive halogen atoms oxidise the less reactive halide ions causing them to lose electrons and form halogen atoms.
