Zusammenfassung der Ressource
Bonding
- Ionic Compounds
- Chemical bonds
- There are 3 types of
strong chemical bonds
- Ionic
- Metallic
- Covalent
- Ionic Bonding
- Ions are formed when atoms gain or lose
electrons, giving them an overall charge
- Ions have a complete outer
shell of electrons
- Ionic bonding involves a transfer of electrons
from metal atoms to non-metal atoms
- The metal atoms lose electrons to
become positively charged ions
- non-metal atoms gain electrons to
become negatively charged ions
- the ionic bond is a strong electrostatic force
of attraction between the positive metal ion
and the negative non-metal ion
- Properties of ionic
compounds
- ionic compounds are giant
structures of ions
- They are held together by
strong forces of attraction
that act in all directions
between oppositely charged
ions
- ionic compounds
- high melting and
boiling points
- don`t conduct
electricity when solid
because the ions can`t
move
- conduct electricity when molten because
the particles are free to move and carry
their charge
- Covalent Bonding
- A covalent bond is a shared pair of
electrons between atoms
- where covalent bonds
occur
- non-metallic elements
- compounds of non-metals
- covalent bonds in
molecules can be
shown using dot and
cross diagrams
- covalent bonds are very strong
- Small Molecules
- small molecules contain a
relatively small number of
non-metal atoms joined by
covalent bonds
- the molecules have no overall
charge, so they can`t conduct
electricity
- substance that consist of
small molecules usually
have low melting and
boiling points
- this is because of weak
intermolecular forces
between the molecules
- these intermolecular forces are
very weak compared to the
strength of the covalent bondsin
the molecules themselves
- the larger the molecules are the
stronger the intermolecular forces
between the molecules become
- larger molecules have
higher melting and boiling
points
- giant covalent structures
- all the atoms in giant covalent structures are
linked by strong covalent bonds
- these bonds must be broken
for the substance to melt or
boil
- means that giant covalent
structures have very high melting
and boiling points
- diamond is a form of carbon
- giant, rigid covalent structure
(lattice)
- each carbon atom
forms four strong
covalent bonds with
other carbon atoms
- all the strong covalent bonds
mean that it is a very hard
substance with a very high melting
point
- no charged
particles, so it
doesn`t conduct
electricity