Melting, Boiling point and electronegativity

Why does the melting and boiling point from Na —> Mg —> Al increase?

• strong electrostatic attraction between metal ions and delocalised electrons

• more valence e electrons

• stronger charge

Why is Si the highest melting point ?

• macromolecular structure

• have many strong covalent bonds

Why does the melting and boiling point from

P4—> S8—> Cl2 become low?

• simple molecular structures

• weak van deer waal’s forces between molecules

• bigger molecule -more electron - more vdW

Why is the melting and boiling point of Ar low?

• monatomic

• very week van Der waal’s forces between atoms

What is electronegativity?

The power of an atom to attract the electrons in a covalent bond

Why does electromagnetivity increase across a period?

• more protons in a nucleus

• stronger attraction between nucleus and 2 electrons in a covalent bond

• increased effective nuclear charge

How does the polarity change with electronegativity value?

• larger electromagentivity value can be seen as negative

• moves to the more negative side