The constituent particles of atom are called sub atomic particles. Therefore electron, proton and neutron are sub atomic particles. Later it was understood that protons and neutrons are made up of quarks. These quarks are also sub atomic particles. Recently it is discovered that the Higgs particles or God particles give mass to many particles like protons, neutrons etc.

Robots are automated machines which have many mechanical parts like wheels, arms, fingers, legs etc. Therefore a strong material is needed. For a given size, steel has several times stronger.

(i) The scales on the wings of a morpho butterfly.
(ii) Peacock feathers.

(i) If the particle of a solid is of size less than 100 nm, it is said to be a nano solid, if the particle size exceeds 100 nm, it is a bulk solid.
(ii) Both have same chemical properties. But their mechanical, electrical, optical, magnetic properties differ.

(i) Nano science is the science of objects with typical sizes of 1 - 100 nm. It deals with the study of property change when a matter is divided into nano particles.
(ii) Nanotechnology is a technology involving the design, production, characterisation and applications of nano structured materials.