Bonding Flashcards
What are the 3 types of crystal structures
- giant ionic
- giant covalent
- metallic
Explain the structure of ionic bonding ( non- metal and metal )
-Strong electrostatic force of attraction between the oppositely charged ions
- brittle = if we shift the structure we end up with repulsive forces (+ +) so the structure loses its attraction
- When drawing the structure you must make sure the ions are alternating
Explain the structure of metallic bonding ( non metals )
- Strong electrostatic force of Attraction between the positive ions and delocalised electrons
- Malleable and ductile ( stretched into thin wires)
as the layers of ATOMS in metallic bonding are free to slide of each other
Once metals have been reshaped the metal still retains its strength as we still have metallic bonding
How many types of covalent bonds are there ( non metals)
single bond = shared pair of electrons (2 electrons)
Double bond = 2 shared pair of electron’s (4 electron’s )
Triple bond = 3 shared pair of electrons ( 6 electrons )
What are the mac molecular types of covalent bonding
Diamond
Graphite
Silicon
What are the molecular types of covalent bonding
Group 7 atoms but they have a covalent bonds as there are a molecule but BETWEEN the molecules are vandeer walls forces
Explain the properties of ionic bonding
High melting point - strong force of attraction between oppositely charged ions so requires large amounts of energy to break these forces
- the more higher the charge the stronger the electrostatic force of attraction
Conduct heat and electricity when molten or dissolved in a solution as the ions are free to move
Explain the properties of molecular colvent
Eg. Idoine
Low boiling pint - weak vander waals forces which don’t require a lot of energy to break
they have a covalent bonds as there are a molecule (group 7 are dative atoms ) but BETWEEN the molecules are vandeer walls forces
Explain the properties of metalic bonding
High melting point - strong attraction between the positive ions and delocalised electrons so a lot of energy is needed to break the structure
- increased charge on the metal ion = stronger attraction and number of delocalised electrons increase
Conducts electricity and heat - delocalised electrons can carry the charge through the structure
describe the structure and bonding in graphite and explain why it has a high melting point
-each carbon is covalently bonded to 3 other carbon atoms to form hexagonal layers. = GIANT COVALENT STRUCTURE
-Between the layers there are weak vander waals forces (layer are free to slide over each other)
-the covalent bonds are strong and require large amounts of energy to break
describe the structure and bonding of Diamond
and explain why it has a high melting point
-each carbon is covalently bonded to 4 other carbon atoms allowing a
-giant covalent structure which
-diamond to be very hard as its in a fixed position and
-requires large amounts of energy to break due to strong covalent bonds
why can graphite conduct electricity but diamond is not able to
graphite= each carbon delocalises an electrons which is able to carry the charge through the structure
diamond= no delocalised electrons or free moving ions
explain why iodine vaporises when heated gently
Vander Waals forces
between the molecules which require little energy to overcome
state why iodine is a poor conductor of electricity
no free delocalised electrons
explain in terms of its structure and bonding why titanium has a high melting point
titanium has metallic bonding which consists of a strong electrostatic force of attraction between the delocalised electrons and the positive ion causing large amounts of energy needed to break the force
why are metals malleable
in metallic bonding the layers of positive ions are free to slide over each other
explain why the melting point of aluminium is higher then the melting point of sodium
aluminium forms a 3+ charge while sodium forms a 1+ charge so aluminium has a greater charge = more delocalised electrons= stronger electrostatic force of attraction which requires more energy to break
what are the 3 types of intermolecular forces
Vander Waals forces - weakest
dipole-dipole
hydrogen bonding- stongest
* intermolecular forces are much weaker than covalent,ionic, or metallic
how are polar bonds made
in a covalent (non-metals) there is a difference in electronegativity between two atoms this allows electrons to be pulled towards the more electronegative atom
in a covalent bond, how can it be a non-polar bond
if the bond is between the same two non-metals this allows an equal electronegativity so the electrons are equally attracted to both atoms
how are dipole-dipole forces created
in a POLAR BOND there is an electron density switch due to the unequal electronegativity this creates permanent dipoles (s+)(s-)
how can some molecules not have a polar bond
if there is more than one covalent bond this allows the polar bond to be arranged symmetrically so the charges cancel out and there are no permanent dipoles anymore
how are Vander Waals forces created
electrons are always moving really quickly in the charged cloud this causes a constant electron density switch which creates temporary dipole which are known as van deer waals forces
what dose vandeer waals force cause
all atoms and molecules to be attracted to each other as the dipoles are constantly being created and destroyed this allows an overall effect of atoms to be attracted to each other
