chemistry

• Chemical reactions involve the breaking and forming of chemical bonds.
• johnstone G.Stoney named electrons
• Ernest Rutherford proposed the nuclear model of the atom based on his experiments with alpha particle scattering from gold foil, where most alpha particles passed straight through but some were scattered back strongly, indicating the presence of a dense nucleus at the center of the atom.
• Isotopes are atoms of the same element with different numbers of neutrons.
• JJ thomson discovered the electron and cathode rays which are negatively charged particles
• cathode rays travel in straight lines.cathode rays are beam of particles and when electric field is applied they get deflected toward the positively charged plate
• e/m ratio is discovered by J.J thomson
• robert millikan discovered the charge of electon which is 1.602*10-19 by performing the oil drop experiment
• ernest rutherford discovered protons by doing the rutherford gold foil experiment
• positive rays/canal rays travel in straight line and cast a shadow of the objects in there way. they can move paddle wheel placed in there way. when electric field applied they deflect towards the negatively charged plate which are now known as protons
• In rutherford experiment most of the alpha particles moved straight through due to the atom being mostly empty space. some of alpha particles deflected due to like charges(repel due to both being postive).some of the bounced back due to the nucleus being dense and small
• james chardwick discovered neutrons
• the electromagnetic spectrum consist of radio waves, microwaves, infrared, visible light, ultraviolet, x-rays, gamma rays ranging from low to high frequency .radio waves are used for radio and tv broadcasting. microwaves are used in micro ovens. infrared is used in cameras. visible light is the region that can be seen. ultraviolet is used in killing bacteria. x-rays are used in taking x rays. gamma rays are used in treating cancer.
• metabolism is sum of all chemical activities taking place in an organism