- Phenomenon of radioactivity was first discovered by A.H.Bacquerel in 1896 while studying fluorescence and phosphorence of compounds irradiated by visible light
- these phosphorescent materials glow in dark after being exposed to visible light
- while conducting experiment on uranium salts, he found that uranium salts has a capability to blacken the photographic plate kept in a dark place wrapped through a paper
- Subsequent experiments showed that radioactivity is a nuclear phenomenon in which an unstable nucleus under goes a decay process referred as radioactive decay
- There are three types of radioactivity decays that occur in nature .These are α decay ,β decay and γ decay.
- We now define radioactive decay as the process by which unstable atomic nucleus looses energy by emitting ionizing particles or radiations ( α,β and γ rays)
- Radioactive decay of an atomic nucleus is a spontaneous process and can occur without any interaction of other particles outside the atom
- This process of radioactive decay is random and we can not predict whether a given radioactive atom will emit radiations at a particular instant of time or not
- Phenomenon of radioactivity is observed in heavy elements like uranium and unstable isotopes like carbon 14
Introduction to radioactivity
at 3:03:00 AM
Class 9 physics notes on chapter motion is now available at the following link CLASS 9 MOTION NOTES (FULL LENGTH)
Question1: A charge Q is divided in two parts q and Q - q separated by a distance R. If force between the two charges is maximum, find the ...
Coherent sources are those sources of light which emit continous light waves of same wavelength , same frequency and are in same phase or h...
Our New Free physics ebooks (pdfs) are available at this link . Hope you lile them.
Unit I: Physical World and Measurement (Periods 10) Physics: Scope and excitement; nature of physical laws; Physics, technology and society...
ADVANTAGES The generation of A.C. is cheaper than that of D.C. A.C. machines are simple , robust and do mot require much attention for the...
Hi all here in this article i am giving some tips and tricks to solve problems in mechanics. To master problem solving skill you need to pra...
1.A particle moves in a straight line with retardation proportional to its displacement. Its loss of kinetic energy for any displacement x i...
Many times i have had users ask me a question which book to opt between H.C Verma Concepts of physics and NCERT physics books . My answer ...
Unit I: Electrostatics (Periods 25) Electric charges and their conservation. Coulomb’s law – force between two point charges, forces betwee...