2.3 Period 3 Flashcards
What links to the melting points of period 3 elements
Bond strength and structure
Which three, period 3 elements have metallic bonding
look at periodic table
sodium
magnesium
aluminium
Explain the trend in melting point from sodium to aluminium
Melting points increase
due to greater positive charged ions
(Na+1, Mg+2, Al+3)
which means more electrons are released into the sea of electrons, and there is stronger electrostatic forces of attraction.
Explain the high melting point in Sillicon
Macromolecular
Strong (Giant) covalent structure
Require alot of energy to overcome the covalent bonds
therefore high metling point
What is the melting point of sillicon like
High
strong covalent bonds
What kind of molecule is phosphorus/ sulfur/ chlorine
Simple covalent molecules
What are the metling points like of Phosphorus, sulfure and chlorine
Kinda low
Explain the melting points of phosphorus, sulfur and chlorine
Low metling points
because they are simple covalent structures
held with weak van der walls forces
weakest intermoelcular force
easy to overcome
What is the melting point of Argon like
Very low
literally a gas at room temperature
Explain the metling point of Argon
Nbole gas, single atom with full outer shell of electrons
Atom is very stable
Van Der Waals between them very weak
therefore easy to overcome at lower temperatures
What is more reactive between sodium and magnesium
Sodium
Why is sodium more reactive than magnesium
- Sodium only has to lose one electron to form an ion
- whereas magnesium has to lose two ions
- erefore less energy is required to ionise sodium
- making it easier to react and more reactive
What are the equations for when sodium and magnesium reacts with water
2Na(s) + 2H2O(l) –> 2NaOH(aq) + H2
Mg + 2H2O –> Mg(OH)2(aq) + H2
What do you see when you react magnesium with steam
- violent reaction
- burns with bright white flame
Whats the equation for reacting magnesiumw with steam
Mg (s) + H2O (g) –> MgO (s) + H2(g)
