অনার্স অ্যাসাইনমেন্ট প্রশ্ন
Honors Assignment It is a general belief that dust is very harmful to us. But this is only
one side of the picture. Dust is also very useful to us. But what is
dust? How is it formed? Every solid substance is composed of
অনার্স এসাইনমেন্ট প্রশ্ন
very small particles. When these small particles of matter are
scattered, they become dust particles. For example, if we break a
brick or a stone into small pieces, it will turn into small particles
of dust. There are different ways by which dust is formed. When
solid things break, dust is formed. Smoke which is generated by
the burning of coal, wood, petrol ete also produces dust. Dust
particles also come from plants, animal matter, sea salt, desert and
ash from volcanoes. These particles that get mixed with air are
called dust. Air carries dust particles from one place to another.
The particles of the earth’s surface also fly in the air in the form of
dust. Jhe biggest utility of dust particles is that they help in the
formation of rain. The water vapours in the clouds condense on
dust particles in the form of water drops. These drops fall on the
carth as rain. So, if there is no dust particle, rain will come late.
Dust also helps to form mist, fog etc.
The dust particles which are present in the air, scatter sunrise in all
directions. Because of this, there is no complete darkness even
long after the sunset. We see red colour in the sky at sunrise and
sunset because of dust particles. In this way, we see that the dust
particles which are thought to be harmful are often very useful too.
Honors Assignment Questions