Hii! I need help sith these questions! best answer will be marked Brainliest, and other benifits! ^^
;; Describe how ice, water, and water vapour can be changed into one another
;; Explain why solid does not flow, but a liquid does
;; Explain why a liquid has fixed volume but not a fixed shape
;; Explain why a liquid expands and contracts on being heated and cooled respectively
;; Describe an experiment to show that a gas expands on being heated and contracts on cooling
;; Explain how, on being heated, a solid changes to a liquid forms a gas
;; Describe an experiment to show sublimation
;; What do you mean by Brownian movement? Why does it take place?
Answers
Answer:
1) When heat (a form of energy) is added, the ice melts into liquid water. It has reached its melting point – 0°C. Continue to apply heat, and the water will turn into water vapour, which is water in its gaseous state. ... If heat is removed from water vapour, the gas cools down and it condenses back into liquid water.
2) In solids there is a strong force of attraction between the molecules and the space between them is very negligible. ... They do not attract each other as strongly as the molecules of solids. Thus, the intermolecular spaces are larger and the molecules are able to move about more freely. This makes a liquid flow.
3) Liquids. ... In a liquid, the particles are still in close contact, so liquids have a definite volume. However, because the particles can move about each other rather freely, a liquid has no definite shape and takes a shape dictated by its container.
4) As the molecules of a liquid are cooled they slow down. As the molecules slow down they take up less volume. Taking up less room because of the molecules lower energy causes the liquid to contract.
5) Observe the bubbles of air inthe water. Now allow the beaker to cool. As the air inside the flask contracts, the water rises up the tube. This proves that gas like air expands on heating and contracts on cooling.
6) The change from solid to liquid is called melting or fusion. When a liquid is steadily heated, the particles move rapidly until many of them have sufficient energy to escape from the liquid and form a gas. This change of state is called evaporation.
7) Take a piece of dry ice and add heat and pressure to it, soon you will observe that the solid ice start escaping into the air and its size reduces. Thus, without turning into the liquid, solid ice sublimes. In our daily lives, camphor and iodine are quite common example that sublime on heating.
8) The random motion of the particles suspended in a fluid (liquid or gas) results from the bombardment. by the fast-moving atoms or molecules in the fluid (liquid or gas). This haphazard motion of the particles is known as Bownian motion.