unit 1 - Bonding + Properties Flashcards
explain covalent bonding
two positive nuclei from different atoms are held together by their common attraction to the shared pair of electrons between them
why are covalent molecules usually gas at room temperature (have low mp/bp)
the bonds between them are weak and easy to overcome
explain ionic bonding
ionic bonding is the electrostatic force of attraction between a positively charged metal ion and a negatively charged non-metal ion
why can ionic compounds only conduct when liquid or dissolved
when liquid or dissolved, the ions are free to move
why do ionic compounds have high melting and boiling point
they contain millions of strong ionic bonds which must be broken
why do covalent networks never conduct
they have no ions which are free to move
why do covalent networks have high mp/bp
they contain many covalent bonds which must be broken
why may some covalent molecules have a higher melting/boiling point than expected
they may be able to form additional bonds between molecules (water can do this)
what is a molecule
a group of atoms held together by covalent bonds
covalent molecular substances contain _______? (bonds)
strong covalent bonds within a molecule + weak bonds between molecules
when are ions formed
when an atom loses or gains electrons to form the stable electron arrangement of a noble gas
