To 'have a chip on your shoulder' means to have an irrational resentment directed at other people (especially those who are not a member of a group or community which you identify with) because of a sense of inferiority (or an erroneous impression that others see you as inferior).
Part of the Nanotechnology glossary: A nanometer is a unit of spatial measurement that is 10-9 meter, or one billionth of a meter. It is commonly used in nanotechnology, the building of extremely small machines. This was last updated in September 2005. Contributor(s): Ian Pulham.
Some students will know nothing, some will be well informed. Most students will probably know that nano means something small, but may not know how small. Tell the students that there are 1 billion (1,000,000,000) nanometers in a meter. Each of them brought in an object. Tell them that the object they brought in is to represent 1 nanometer and you'd like to know where the millionth one is located.