Question

Which of the following ranges of particle size defines nano scale ?

• A. \(10\text{-}100\) nm
• B. \(1000\text{-}2000\) nm
• C. \(1\text{-}100\) nm
• D. \(100\text{-}1000\) nm

Hint:

Nanoscale is 1 to 100 nanometres.

Answer 1

The Correct Option is C

Step 1: Understand the concept
Nanoscience deals with materials whose size is measured in nanometres. A nanometre is \(10^{-9}\) m.

Step 2: State the range
By the usual definition, the nanoscale lies between 1 nm and 100 nm in at least one dimension.

Step 3: Compare with the options
Option (A) 10-100 nm leaves out the 1-10 nm range, which still counts as nano. Options (B) 1000-2000 nm and (D) 100-1000 nm correspond to particles of micrometre size.

Step 4: Conclusion
Hence 1-100 nm is the right range.

Final Answer:
Nano scale means 1-100 nm. This is option (C). \[ \boxed{\text{(C) }1\text{-}100\ \text{nm}} \]