Period Three Elements Flashcards
What is the structure of sodium
Soft
Giant metallic
What is the structure of magnesium?
Giant metallic silver coloured
Higher change density so more hard
What is the structure of aluminium?
Silver coloured metal
Higher charge density as 3+ ion
Giant metallic
What is the structure of silicon?
Shiny solid Non metal Giant covalent Can conduct V high MP
What is the structure of phosphorus?
Red white solid Non metal Simple covalent Lower MP than silicon Bonds to itself like graphite
What is the structure of sulphur?
8 sulphur arranged in octagon
Non metal
Simple covalent
Higher MP than phosphorus bc higher vdw
What is the structure of chlorine?
Simple ionic Non metal Green gas Diatomic Lower mo than S and P
What is the structure of argon?
Colourless gas
Inert
Non metal
Atomic as no bonding
How does period three react with water?
Na - vigorous
Mg - slow with cold water or faster with heat and steam
Cl2 - dissolves in water
Give the equation for the reaction of sodium in water:
2Na + 2H20 to 2NaOH +H2
Produces squeaky pop
Give the reactions of magnesium with water:
Cold water:
Mg + 2H20 to Mg(0H)2 + H2
Steam:
Mg + H20 to Mg0 + H2
Give the equation for chlorine dissolving in water:
Cl2 + H20 to HCl0 + HCl
(Reversible in sunlight)
This forms acids of pH of 1-2
Can be used for sterilisation of swimming pools
How does sodium react with oxygen, what colour does it burn?
Vigorous
Yellow flame
2Na + 1/2 O2 to Na20
How does magnesium react with oxygen, what colour does it burn?
Vigorous
Bright white flame
Mg + 1/202 to Mg0
How does aluminium react with oxygen, what colour does it burn?
Slowly
Bright white flame
2Al + 1 and 1/2 02 to Al203
How does silicon react with oxygen, what colour does it burn?
Slow
Si+02 to Si02
How does phosphorus react with oxygen, what colour does it burn?
Very vigorous
Bright white flame
P4 + 502 to P4010
How does sulphur react with oxygen, what colour does it burn?
Fairly reactive Blue flame S + 02 to S02 With catalyst and higher temp: S02 + 1/202 to S03
First ionisation energy
The energy required to remove one mole of electrons from one mole of gaseous atoms to produce one mole of gaseous +1 ions
What is the trend in ionisation energies?
Increases along the period
Except al has lower ie than mg bc it has electrons in a higher sub shell so more shielding
Except s has lower ie than p bc shielding is identical but s has 2 electrons in its outer shell and these repel each other making it easier to remove and electron
How does atomic radius change across the period?
It decreases due to increased nuclear change and similar shielding
What is the trend in melting and boiling points across the period?
Increase Na through to Al then decrease Al to Ar
Increased bc on strong metallic bonding with nuclear radius getting smaller and nuclear charge getting bigger
Si has high MP and BP bc of giant covalent structure, covalent bonds are v strong
The following 4 elements are simple molecular the element with the highest M/Bp is sulphur bc it’s the biggest molecule so has the greatest VdW
What is the trend in acid base behaviour along the group?
LHS is strongly basic
RHS is strongly acidic
The middle is amphoteric
How does sodium oxide react with water and acids?
Na20 + H20 to 2NaOH
How does sodium oxide react with water and acids?
Mg0 + H20 to Mg(OH)2
MgO + 2HCl to MgCl2 + H20
How does aluminium oxide react with water and acids?
its amphoteric so reacts with all except water
Al2O3 + HCl to 2AlCl3 + 3H20
Al2O3 +3 H20 + 2NaOH to 2NaAl(OH)4
How does sulphur dioxide oxide react with water?
SO₂ + H₂O——->H₂SO₃
How does sulphur trioxide react with water?
SO3 (g) + H2O (l) → H2SO4 (aq)
