States of Matter

fact

Sieving is the method in which a sieve or the strainer is used which has small holes. Only fine particles can pass through these holes, whereas the bigger ones stay in the sieve. 

Evaporation is a process of conversion of liquid into vapours. Water gets evaporated, mud settles down and it is salt which is recovered by evaporation.  

Milk when heated gives off water in the form of vapours. When milk is heated with the vessel covered, then water vapours can be observed on the inner surface of the lid. 

Solute in lower quantity is dissolved in a solvent. The mixture of the two is known as solution. 

The solubility of any substance can be increased by increasing the temperature of the solution. 

Sugar or any solute gets dissolved quickly when the temperature is higher. As hot coffee, soup, and boiled milk are hot, so sugar will quickly dissolve in these. Iced tea being at lower temperature will take longer time to dissolve sugar. 

Heterogeneous mixture is the one in which the solute and solvent can be seen separately as the two do not get dissolved e.g. a mixture of sand and water, sugar and sand, rice and water etc. 

The substances which are made up of only one type of particles are known as pure substances. On the other hand, the substances made up of more than one type of particles are known as mixtures. Different components forming the mixtures are known as constituents. 

Mixture is any substance which is made up of 2 or more types of particles e.g. sea water is a mixture of water and dissolved salts, air is a mixture of gases and water vapors, pickle is a mixture of oil, salt, spices etc. But common salt is a compound (NaCl) and not a mixture. 

Evaporation refers to conversion of a liquid into its vapour state and condensation refers to the conversion of vapours back to the liquid state. 

Sand is heavier than water and settles down at the bottom. Vinegar and sugar both are water-soluble, but oil is lighter than water and floats on the surface.  

Only those materials sink in water which are insoluble and are heavier than water, e.g. sand, soil etc. Oil and sawdust are lighter than water and remain at the surface. 

Substances soluble in water disappear in water. The softness or the hardness of the substance do not play any role in this.  

Vinegar, salt and sugar get easily dissolved in water and are said to be water soluble. Sawdust remains separate when added to water and is said to be water insoluble.