Question

information regarding periodical development of fundamental particles and structure of atom

Answer 1

The atoms are made up of matters these matters are very smallar particles . These parties can never be destroyed or breakage further.

The atomic theories are different as time by time scientist developed.

The first theory was proposed by Jan Dalton that atom is fundamental particles which can be found in all elements.

The 2ndly theories then advanced as Andrew Millikan and Chadwick gaves the information about electrons present in atoms latter they concludes the mass of electrons.

Latter protons and neutrons developed and then charges discovered,

Then scientist says the protons and neutrons is mass of atom .

And arrangement of atoms by their increasing orders of atom no.

This arrangement can be sequenced by increasing size of atoms.

The sequence of placing atoms in periodic table by Mendlive periodic table gives the groups and periods.

The left to right is periods ,and up down was groups. Up to down shows the size of atoms as increasing, and left to right shows the increasing atomic no. Of atoms.

So when time passed the Mendlive periodic table was more advanced and gives the information about melting boiling point and gives the names to periodic table as 1-2 groups are alkaline earth metals and 8 group are noble gas 7 th group are called halogens group which are gases mostly.

Answer 2

Periodical development of fundamental particles :

• About 2600yrs  ago, an Indian sage called Kanada actual called by name Kasyapa proposed that all forms of matter are composed of very small particles called as Anu and each anu may be made up of still smaller particle called Parmanu.

• later Democritus called these atoms [ greek Word "Atomio " meaning indivisible "

• John Dalton atomic theory described elements in terms of atoms which he believed to be small , indivisible particles.

• Later John Dalton's Postulate Atom is indivisible is disproved because through various experiments conducted by scientist three fundamental particles were discovered

1. Electron --- By J.J Thomson in 1897
2. Proton --- By Gold Stein in 1920
3. Neutron --- By James Chadwick in 1932

Structure of Atom:

• Thomson Atomic model:

        After the discovery of electrons J.J Thomson proposed his Plum Pudding model which shows electrons embedded through out the mass of positively charged material.

• Rutherford alpha scattering experiment led to discovery of atomic nucleus.

• Neil Bohr modified Rutherford Model of the atom by stating that electrons move in specific energy levels around Nucleus of atom.

• Later Bohr Sommerfeld model though successful in accounting for the spectral line of H2 spectra but did not provide satisfactory picture of the structure of atom in general.

• At last A quantum mechanical model of atom was developed by Erwin Schrodinger. According to this model, electrons are present in a particular region or space around the nucleus called as Orbital where probability of finding electrons are more.