CY3151- ENGG CHEMISTRY UNIT-II/NANOCHEMISTRY

Nanomaterials are the materials having components with size less than____ at least in one dimension.

• 10 nm

• 100 nm

• 10 m

• 100 m

1. Match the nanomaterials with their dimensions: 1. Quantum dots- zero dimension; 2. Nanowires and Nanorods - one dimesion; 3. Thin films - two dimension;

• 1,2,3 are correct

• 1,2,3 are incorrect

• 1,2 are correct; 3 is incorrect;

• 1,3 are incorrect; 2 is correct;

Surface area of nano particles is more than the bulk materials.

• True

• False

The following properties of materials are increasing at nanoscale.

• Strength

• Melting point

• Hardness

• Ductility

______ are fine aggregates of atoms or molecules.

• Nanoclusters

• nanorods

• Nanotubes

• Nanowires

Nanowire is one dimesional cylindrical solid material having an aspect ratio greater than 20

• True

• False

Nanowires can be synthesized by: Mehtod A: Template assisted synthesis; Method B: VLS;

• Method A only

• Method B only

• Method A & Method B

Carbon nanotubes can be prepared by

• Pyrolysis

• Laser evaporation

• Both methods

Laser ablation involves the vapourization of graphite target containing small amount of cobalt and nickel.

• True

• False

1.________ process involves building-up of materials from the bottom by atom by atoms, molecule by molecule and 2._______ process involves the conversion of bulk materials into smaller particles of nano-scale structure.1.

• 1. 1.Top-down; 2.bottom-up;

• 1. 1. bottom-up; 2.Top-down;