11th class Structure of an atom Handwriting notes pdf

Notes link description box
#aniketncert

#atomicstructure

Handwriting notes class 11


Unit- 2


Chapter- Structure of an atom


Introductions: 


The existence of atoms has been proposed since the time of early Indian and Greek philosophers (400 B.C.) who were of the view that atoms are the fundamental building blocks of matter. According to them, the continued subdivisions of matter would ultimately yield atoms which would not be further divisible. The word ‘atom’ has been derived from the Greek word ‘a-tomio’ which means ‘uncutable’ or ‘non-divisible’. 


These earlier ideas were mere speculations and there was no way to test them experimentally. These ideas remained dormant for a very long time and were revived again by scientists in the nineteenth century.


The atomic theory of matter was first proposed on a firm scientific basis by John Dalton, a British school teacher in 1808. His theory, called Dalton’s atomic theory, regarded the atom as the ultimate particle of matter (Unit 1).


In this unit we start with the experimental

observations made by scientists towards the end of nineteenth and beginning of twentieth century. These established that atoms can be further divided into sub-atomic particles, i.e., electrons, protons and neutron a concept very different from that of Dalton.The major problems before the scientists at that time 




Discovery of Electron 


In 1830, Michael Faraday indicated that if power is gone through an answer of an electrolyte, concoction responses happened at the terminals, which brought about the freedom what's more, affidavit of issue at the cathodes. He figured certain laws which you will contemplate in class XII. These outcomes recommended the particulate nature of power. 


A knowledge into the structure of particle was 

gotten from the analyses on electrical 

release through gases. Before we talk about 

these outcomes we have to remember a fundamental rule with respect to the conduct of charged particles : "Like charges repulse one another and dissimilar to charges draw in one another". 

In mid 1850s numerous researchers predominantly 


Faraday started to examine electrical release 

in incompletely cleared cylinders, known as 

cathode beam release tubes. A cathode beam tube is made of glass.containing two slender bits of metal, called 

cathodes, fixed in it. The electrical release through the gases could be watched uniquely at extremely low weights and at exceptionally high voltages. The weight of various gases could be balanced by clearing. When adequately high voltage is applied over the terminals, current beginnings streaming

Notes link here

https://www.gkncertsolution.in/2020/04/class-11-handwriting-notes-pdf.html?m=1