Periods 3 Elements And Oxides Flashcards
Why is sodium more reactive than magnesium?
When they react sodium loses one electron to form Na+ ions , while magnesium loses 2 electrons to form Mg2+
It takes more energy to lose 2 electrons than it takes to lose 1
Therefore more energy needed for magnesium to react
WhaT is the structure of silicon?
Macromolecular with a tetrahedral structure.
Why does silicon have a high boiling point ?
There are strong covalent bonds. A lot of energy us needed to break these bonds
What do the melting points of phosphorus, sulfur and chlorine depend on ?
They are all molecular. The strength of van der waals forces
Why do the elements phosphorus, sulfur and chlorine have low melting points?
Because van der waals forces are weak and easy to overcome
Why does sulfur have a higher boiling point than phosphorus ?
Because more atoms in a molecule mean stronger van der waals forces and sulfur molecule is S8 so it’s got a higher melting point than phosphorus and chlorine
Why has argon got a very low melting point ?
Because it exists as individual atoms resulting in very weak van der waals forces
As you go across a period what happens to the atomic radius ?
It decreases
