Periodicity Year 2 Flashcards
(19 cards)
What’s the trend in physical properties along group 3
Metals to non metals
Describe physical properties of Na Mg Al
Na Mg Al are metallic= shiny, conduct, react with dilute acids to give hydrogen and salts
Describe physical properties of Si
Metalloid
Conducts to some extent- useful for making semiconducting devices
Describe physical properties of P S Cl
Typical non metals= dont conduct, low mp and bps
Describe physical properties of Ar
Noble gas= chemically unreactive and exists as separate atoms
What type of reactions do period 3 elements undergo
Redox reactions since every element starts with a oxi state of 0 and after reacting ends up with positive or negative state
Which period 3 elements react with water
Sodium and magnesium
Chlorine is the only non metals that reacts with water
Describe the reaction of sodium with water
Vigorous
It floats and fizzes rapidly
It melts because of the heat released
A strongly alkaline solution of sodium hydroxide is produced (ph of 13-14)
Describe the reaction of magnesium with water
Very slow at room temp
Few bubbles of hydrogen are formed after some days
Less alkali than sodium as magnesium is only sparingly soluble (ph around 10)
Produces magnesum hydroxide and hydrogen
Describe the reaction of heated magnesium with steam
Produces magnesium oxide and hydrogen
Much faster
Describe when period 3 elements react with oxygen
All exothermic
How does sodium react with oxygen
Brightly in air
Yellow flame
Forms white sodium oxide
How does magnesium react with oxygen
A strip of Mg burns in air
Bright white flame
Magnesium oxide white powder produced
How does aluminum react with oxygen
Al powder is heated and lowered into a jar of oxygen
Burns brightly to give aluminum oxide white powder
Appears to be unreactive as its always coated with strongly bonded surface layer of oxide
Even if the surface is scratched it reacts rapidly to replace it
How does silicone react with oxygen
If its heated strongly in oxygen
How does phosphorous react with oxygen
Red P must be heated before
White P spontaneously ignites in air and a white smoke of phosphorous pentoxide is given off
The red and white are allotropes of phosphorus (same element arranged differently)
How does phosphorus react with oxygen if the oxygen supply is limited
Phosphorus trioxide is also formed
How does sulfur react with oxygen
When sulfur powder is heated and lowered into a heated jar of oxygen
Burns with a blue flame to form colorless gas sulfur dioxide and a small amount of sulfur trioxide
How do the oxi states change in these redox reactions
Period 3 elements increase
Oxygen decreases from 0 to -2
The oxi no. Increases across the period of the period 3 elements
