solids Flashcards
what are the forces holding molecules together?
weak intermolecular forces
what are the 2 types of electron sets?
bonding and non bonding
electron sets
electron sets will always _____ each other
repel
the water molecule has _____electron sets around it
4 electron sets (2 bonding sets and 2 non bonding) sets)
what are the particles in diamond?
Carbon atoms
what are the forces of attraction in diamond?
strong covalent bonds between each C atom
what is the shape of a water molecule and what is the approximate bond angle?
bent shape approx 109 degress
what type of compound is diamond?
Giant covalent network
Diamond and graphite are both giant covalent networks however however they have 2 different physical properties - list these
Diamond will not conduct electricity as all valence electrons are involved in bonding, where graphite will conduct due to the presence of free moving electrons between layers.
Graphite can act as a lubricant because of the weak forces of attraction between layers
give the number of valence electrons for B and Be for a full shell
Be has a maximum of 4 electrons
B has a maximum of 6 electrons
BF3 will have what shape with what bond angle
trigonal planner with a bond angle of 120 deg
BeCl2 will have what shape with what bond angle
bent or V shaped with a bond angle of approx 109 deg
while water has an overall bent shape due to the position of the bonding sets of electrons - the shape of all electron sets around the central O atom is ?
tetrahedral - due to the repulsion of all 4 sets of electrons
(2 bonding sets and 2 non bonding sets)
Ag, Cu ,Pb and Mg are all examples of …
metals
the structure of a metal consists of …
metal atoms (or ions) surrounded by delocalised MOBILE electrons
NaCl , MgO, CaCO3 and KF are examples of…
ionic compounds
NaCl can conduct only when? 2 answers
molten or dissolved in water
Why can MgO conduct when molten but not when solid
When molten there are MOBILE (or free moving) IONS to carry charge.
In the solid form the ions are not free to move and carry charge
Why can giant covalent network substance not dissolve in water
The positive and negative ends of the polar water molecule are not strong enough to overcome the strong attractive forces of the covalently bonded atoms
Why can polar water dissolve ionic compounds such as MgCl2
The +ve and -ve ends of the polar water molecule are able to break the attractive forces between Mg2+ and Cl- ions
