Showing posts with label General knowledge. Show all posts
Showing posts with label General knowledge. Show all posts

Some Information About Atoms

The theory  that metter  was made  from small indivisible particles called atoms  date back to some five centuries  B.C  to democritos and a century B.C  to a roman poet leukiphos. 

This theory was put on sound scientific  basis by jonh Dalton in 1808.


Today it is well established  that atoms are complex  organizations of metter and energy . Many particles  have been discovered  within the atoms.
   
These sub atomic particles include electron, proton, neutron , and several  types  of mesons  and hyprons etc. since electron, proton and neutron in the atom play a major  role in determining the chemical and physical properties of metter.

 we will, therefore, restrict ourselves  to the study of these particles.
edvidence for the presence of electron, proton and neutron in the atom is derived through many experiments such as:

  1. Faraday's experiment  indicates the existence of electrons.
  2. crooke's tube experiments show the presence of electron and proton in the atoms.
  3. Radioactivity further comfirms the presence of electrons and proton.
  4. chadwick experiments show the presence of neutron.
  5. Spectrosocpic experiments reveal the electronic structure of atoms. 
These are discussed  one by one

Joseph Priestley Discovery Oxygen


                                                   August 1, 1774

oxygen had been produced by several chemists prior to its discovery in 1774 but they failed to recognise it as a disitinct element.

Joseph priestley and carl wilhelm scheele both independently discovered oxygen, but priestly is usually given credit for the discovery.

On this day, prisestley heated some mercuric oxide powder discovery that it gave off a gas that could reignite a glowing ember.

He  collected large amountsof the gas and tried breathing its himself. after a few puffs, priestley was hooked .

He declared, "My Chest felt peculiarly light and easy for some time afterword."