Period 3 Year 1/2 Flashcards
What are the trends in atomic radius?
Decreases as you go across a period.
Why does the atomic radius decrease
As the proton number increases so it attracts the outer electrons towards the nucleus.
How does first ionisation energy differ across a period?
Increases across a period
Where does the trend of ionisation energy change?
Dip for period 3 and dip for period 6
What is the bonding for Na Mg and Al?
Metallic bonding
What is the bonding got silicon
Giant covalent bonding
What is the bonding for P,S,Cl?
Covalent bonding
What is the melting point for Al,Mg and Na
Al is the strongest as has more electrostatic attraction! Stronger metallic bonding.
Then Mg and Na
What is the melting point of silicon
As it is a macromolecule
High melting point
Which element ihas the highest met,int point out of P,S,Cl?
S8,P4, Cl2
As more stronger van der walls forces
What are properties of metal?
Shiny
Conduct electricity
React with dilute acids to give hydrogen and salts.
What are properties of Silicon?
Conduct electricity
useful semiconductors
What are properties of phosphorus, sulfur, chlorine?
They do not conduct electricity and have low boiling points and melting points.
What metals react with cold water?
Sodium and magnesium
What happens when sodium reacts with water?
It is a vigorous reaction.
Sodium floats on the surface of the water and fizzes rapidly because of the heat released by reaction. Produces w strong alkaline
What happens when magnesium reacts with cold water?
It is a very slow reaction and only a few hydrogens particles form.
How does magnesium react with steam?
Mg(s) + H2O(g) —> MgO (s) +H2(g)
this is a much faster reaction.
What are reactions with oxygen?
The reactions are exothermic.
How does sodium react with oxygen?
It burns brightly- with yellow flames Form a white sodium oxide
Equation for sodium reacting with oxygen.
2Na(s) + 1/2O2 (g) —> Na2O(s)
How does magnesium react with oxygen?
It burns in air with a bright white flame. A white powder is produced (magnesium oxide).
If magnesium was burned and lowered into a gas jar of oxygen- the flame is even more intense.
How does Aluminium react with oxygen?
If heated and put into a gas jar of oxygen, it burns brightly to give aluminum dioxide.
How does silicon react with oxygen?
Si(s) + O2–> SiO2(s)
