Give information about examples of colloids.

(N/A) Examples of colloids are as follows:
$(i)$ Blue colour of the sky: Dust particles along with water suspended in air scatter blue light,which reaches our eyes,making the sky appear blue.
$(ii)$ Fog,mist,and rain: When a large mass of air containing dust particles is cooled below its dew point,moisture condenses on these particles,forming fine droplets. These droplets are colloidal and float in the air as mist or fog. Clouds are aerosols with small water droplets suspended in air.
Condensation in the upper atmosphere causes these colloidal droplets to grow until they fall as rain. Rainfall can also occur when two oppositely charged clouds meet. Artificial rain can be induced by spraying electrified sand or a sol with a charge opposite to that of the clouds from an aeroplane.
$(iii)$ Food articles: Milk,butter,halwa,ice-cream,and fruit juices are all colloids.
$(iv)$ Blood: It is a colloidal solution of an albuminoid substance. The styptic action of alum and ferric chloride is due to the coagulation of blood,which forms a clot and stops bleeding.
$(v)$ Soils: Fertile soils are colloidal,with humus acting as a protective colloid. This nature allows soils to absorb moisture and nutrients.
$(vi)$ Formation of delta: River water is a colloidal solution of clay. Sea water contains electrolytes. When river water meets sea water,these electrolytes coagulate the clay,leading to its deposition and the formation of a delta.