838

25. Give an example of a nanomaterial that is >100 years old. 26. An ideal metal would be expected to expel electromagnetic fields (i.e. reflect EM waves). Why do some metals and metallic oxides have colour (even look black)? 27. How can a metal be modified to become black?28. What can be done to mitigate the effect of tunnelling across gate oxides in integrated microelectronics?