Question

What is elasticity? How is it different from viscosity? What is the anatomy of a bubble? Why do bubbles form? What’s hydrophilic substance, how is it different from hydrophobic?

Answer 1

1. Ability of an object to resume its normal shape after being compressed or stretched is called elasticity

2. Viscosity - the material will deform with loading but will have a lag between developing stress and resulting strain - the greater the rate of loading , the greater the stress developed. The energy is absorbed by the material and it will retain its new shape and size.

3. A bubble is just air wrapped in soap film. The outside and inside surfaces of a bubble consists of small molecule. A thin layer of water lies between the two layers of soap molecules.

When soap and water are mixed together and air is blown to the mixture, the sopa forms a thin skin or wall and traps the air which creates a bubble.

4. Hydrophobic - physical property of a molecule that repells water. eg. fats, oils, alkanes and greasy substance

Hydrophilic - means water loving. The molecules that absorb water. e.g. wood, cotton, leather