5. Transition Metals, Nanoparticles and Materials Flashcards
What are the properties of transition metals?
High melting and boiling points; sonorous (ring when struck), lustrous (shiny) multiple oxidation states; produce coloured compounds; are used as catalysts; Relatively unreactive (i.e. with water, oxygen and halogens); hard, strong, dense; malleable/ductile; good electrical/thermal conductors
What is the symbol for manganese?
Mn
What is the symbol for titanium?
Ti
What is the symbol for chromium
Cr
What properties do group 1 metals and transition metals have in common?
sonorous (ring when struck), lustrous (shiny)
malleable/ductile;
good electrical/thermal conductors
What properties do transition metals have that group 1 metals do not have?
High melting and boiling points; multiple oxidation states; produce coloured compounds; are used as catalysts; Relatively unreactive (i.e. with water, oxygen and halogens) hard, strong, dense;
What are the three classifications of particulate matter?
coarse or dust
fine
nanoparticle
What is the size (diameter) range of a nanoparticle?
1 - 100 nm
What is the approximate number of atoms in a nanoparticle?
500
What is the size of an atom?
0.1 nm
What are the risks associated with coarse or dust particles?
They can be inhaled and get stuck in our lungs.
What are the risks associated with fine particles?
They are small enough to get into our blood stream.
What is the relationship between the size of a particle and its surface area to volume ratio?
They are inversely proportional. If the size doubles the surface area to volume ratio halves.
What is the size (diameter) range of a fine particle?
100 nm - 2500 nm
What is the size (diameter) range of a dust or coarse particle?
1 x 10-5 m and 2.5 x 10-6 m
What are the uses of nanoparticles?
Catalysts Medicine delivery Fabrics Cosmetics Electronics
What are some of the potential dangers associated with nanoparticles?
Can get into the blood stream
Can accumulate in the environment with unknown consequences
What is soda-lime glass made from?
sand, sodium carbonate and limestone
What is borosilicate glass made from?
sand and boron trioxide
What is the benefit of borosilicate glass?
It melts at a higher temperature.
What do we make from clay ceramics?
Pottery and bricks
How do we make things from ceramics?
shaping wet clay and then heating in a furnace
Name the two main constituents of a composite.
The matrix and the binder
Give some examples of composite materials
Fibreglass
Carbon fibre
Concrete
Wood
What are the properties of ceramics?
Can be moulded when wet (for clay) or hot (for glass)
Hard, brittle once dried (for clay) or cooled (for glass)
Glass is also often transparent
What are properties of composites?
Strong
Low density
so high strength to weight ratio
How are polymers made?
Combining monomers (often coming from oil) in specific temperatures and conditions.
What are the properties of polymers?
Strong
Low density
so high strength to weight ratio
often transparent
What are the two types of polymer?
Thermosoftneing
Thermosetting
What are the properties of thermosoftneing plastics?
They consist long polymer chains twisted, but not bonded together. There are weak forces between the chains
They will melt and can be remoulded on heating.
They are often more flexible than thermosetting polymers.
What are the properties of thermosetting plastics?
They consist long polymer chains with crosslinking and so strong covalent bonds between the chains.
They will burn on reheating.
They are strong, hard and rigid.
